1 <!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook V3.1//EN"[
2 <!entity % dummy "IGNORE">
3 <!entity supported SYSTEM "supported.sgml">
4 <!entity newfeatures SYSTEM "newfeatures.sgml">
5 <!entity p-intro SYSTEM "privoxy.sgml">
6 <!entity seealso SYSTEM "seealso.sgml">
7 <!entity contacting SYSTEM "contacting.sgml">
8 <!entity history SYSTEM "history.sgml">
9 <!entity copyright SYSTEM "copyright.sgml">
10 <!entity license SYSTEM "license.sgml">
11 <!entity p-version "3.0.27">
12 <!entity p-status "UNRELEASED">
13 <!entity % p-not-stable "INCLUDE">
14 <!entity % p-stable "IGNORE">
15 <!entity % p-text "IGNORE"> <!-- define we are not a text only doc -->
16 <!entity % p-doc "INCLUDE"> <!-- and we are a formal doc -->
17 <!entity % p-supp-userman "INCLUDE"> <!-- Include all from supported.sgml -->
18 <!entity my-copy "©"> <!-- kludge for docbook2man -->
19 <!entity % p-newstuff "INCLUDE"> <!-- exclude stuff from devel versions -->
20 <!entity % seealso-extra "INCLUDE"> <!-- extra stuff from seealso.sgml -->
21 <!entity my-app "<application>Privoxy</application>">
24 File : $Source: /cvsroot/ijbswa/current/doc/source/faq.sgml,v $
27 This file belongs into
28 ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
30 Copyright (C) 2001-2018 Privoxy Developers https://www.privoxy.org/
33 Based partially on the Internet Junkbuster FAQ originally written by and
34 Copyright (C) 1997 Anonymous Coders and Junkbusters Corporation.
35 http://www.junkbusters.com/
37 <Qandaset defaultlabel='qanda'>
52 ========================================================================
53 NOTE: Please read developer-manual/documentation.html before touching
56 Please we keep the info in this file as version independent as possible
57 so we only have to maintain one FAQ. Where significant changes are
58 made to Privoxy configuration, please note the change in such a way that
59 it makes sense to both users of older and newer versions.
60 ========================================================================
66 <article id="index" class="faq">
68 <title>Privoxy Frequently Asked Questions</title>
72 <!-- Completely the wrong markup, but very little is allowed -->
73 <!-- in this part of an article. FIXME -->
74 <link linkend="copyright">Copyright</link> &my-copy; 2001-2018 by
75 <ulink url="https://www.privoxy.org/">Privoxy Developers</ulink>
79 <pubdate>$Id: faq.sgml,v 2.135 2017/03/27 10:22:27 fabiankeil Exp $</pubdate>
83 Note: this should generate a separate page, and a live link to it.
84 But it doesn't for some mysterious reason. Please leave commented
85 unless it can be fixed proper. For the time being, the copyright
86 statement will be in copyright.smgl.
90 <legalnotice id="legalnotice">
92 text goes here ........
102 <orgname>By: Privoxy Developers</orgname>
111 This is here to keep vim syntax file from breaking :/
112 If I knew enough to fix it, I would.
113 PLEASE DO NOT REMOVE! HB: hal@foobox.net
118 This FAQ gives quick answers to frequently asked questions about
119 <ulink url="https://www.privoxy.org/">Privoxy</ulink>.
120 It is not a substitute for the
121 <ulink url="../user-manual/index.html"><citetitle>Privoxy User Manual</citetitle></ulink>.
123 This works, at least in some situtations:
124 Test: <ulink url="privoxy-user-manual.pdf"><citetitle>User Manual</citetitle></ulink>.
128 <!-- Include privoxy.sgml boilerplate: -->
129 <para>What is Privoxy?</para> &p-intro;
130 <!-- end boilerplate -->
133 Please note that this document is a work in progress. This copy represents
134 the state at the release of version &p-version;.
135 You can find the latest version of the document at <ulink
136 url="https://www.privoxy.org/faq/">https://www.privoxy.org/faq/</ulink>.
137 Please see the <link linkend="contact">Contact section</link> if you want to
138 contact the developers.
145 <!-- ~~~~~ New section ~~~~~ -->
147 <sect1 id="general"><title>General Information</title>
148 <sect2 renderas="sect3" id="who-uses"><title>Who should give &my-app; a try?</title>
150 Anyone who is interested in security, privacy, or in
151 finer-grained control over their web and Internet experience.
155 <sect2 renderas="sect3" id="bestchoice"><title>Is Privoxy the best choice for
158 &my-app; is certainly a good choice, especially for those who want more
159 control and security. Those with the willingness to read the documentation
160 and the ability to fine-tune their installation will benefit the most.
163 One of <application>Privoxy's</application>
164 strengths is that it is highly configurable giving you the ability to
165 completely personalize your installation. Being familiar with, or at least
166 having an interest in learning about <ulink
167 url="http://en.wikipedia.org/wiki/Http">HTTP</ulink> and other networking
168 protocols, <ulink url="http://en.wikipedia.org/wiki/Html">HTML</ulink>, and
169 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
170 Expressions</quote></ulink>
171 will be a big plus and will help you get the most out of &my-app;.
172 A new installation just includes a very basic configuration. The user
173 should take this as a starting point only, and enhance it as he or she
174 sees fit. In fact, the user is encouraged, and expected to, fine-tune the
178 Much of <application>Privoxy's</application> configuration can be done
179 with a <ulink url="http://en.wikipedia.org/wiki/Web_browser">Web browser</ulink>.
180 But there are areas where configuration is done using a
181 <ulink url="http://en.wikipedia.org/wiki/Text_editors">text editor</ulink>
182 to edit configuration files. Also note that the web-based action editor
183 doesn't use authentication and should only be enabled in environments
184 where all clients with access to &my-app; listening port can be trusted.
188 <sect2 renderas="sect3" id="proxymoron"><title>What is a <quote>proxy</quote>? How does
189 Privoxy work? </title>
191 A <ulink url="http://en.wikipedia.org/wiki/Proxy_server">web proxy</ulink>
192 is a service, based on a software such as &my-app;, that clients
193 (i.e. browsers) can use instead of connecting to web servers directly.
194 The clients then ask the proxy to request objects (web pages, images, movies etc)
195 on their behalf and to forward the data to the clients.
196 It is a <quote>go-between</quote>. For details, see
197 <ulink url="http://en.wikipedia.org/wiki/Proxy_server">Wikipedia's proxy definition</ulink>.
200 There are many reasons to use web proxies, such as security (firewalling),
201 efficiency (caching) and others, and there are any number of proxies
202 to accommodate those needs.
205 &my-app; is a proxy that is primarily focused on
206 privacy enhancement, ad and junk elimination and freeing the user from
207 restrictions placed on his activities. Sitting between your browser(s) and the Internet,
208 it is in a perfect position to filter outbound personal information that your
209 browser is leaking, as well as inbound junk. It uses a variety of techniques to do
210 this, all of which are under your complete control via the various configuration
211 files and options. Being a proxy also makes it easier to share
212 configurations among multiple browsers and/or users.
216 <sect2 renderas="sect3" id="otherstuff">
217 <title>Does Privoxy do anything more than ad blocking?</title>
219 Yes, ad blocking is but one possible use. There are many, many ways &my-app;
220 can be used to sanitize and customize web browsing.
224 <sect2 renderas="sect3" id="newjb"><title>What is this new version of
225 <quote><citetitle>Junkbuster</citetitle></quote>?</title>
227 <!-- Include history.sgml -->
234 <sect2 renderas="sect3" id="whyprivoxy">
235 <title>Why <quote>Privoxy</quote>? Why change the name from
236 Junkbuster at all?</title>
238 Though outdated, Junkbusters Corporation continued to offer their original
239 version of the <application>Internet Junkbuster</application> for a while,
240 so publishing our <application> Junkbuster</application>-derived software
241 under the same name would have led to confusion.
244 There were also potential legal reasons not to use the
245 <application>Junkbuster</application> name, as it was (and maybe still is)
246 a registered trademark of Junkbusters Corporation.
247 There were, however, no objections from Junkbusters Corporation to the
248 <application>Privoxy</application> project itself, and they, in fact,
249 shared our ideals and goals.
252 The Privoxy developers also believed that there were so many improvements
253 over the original code, that it was time to make a clean break from the past
254 and make a name in their own right.
257 <application>Privoxy</application> is the
258 <quote><emphasis>Privacy Enhancing Proxy</emphasis></quote>. Also, its content
259 modification and junk suppression gives <emphasis>you</emphasis>, the user, more
260 control, more freedom, and allows you to browse your personal and
261 <quote><emphasis>private</emphasis> edition</quote> of the web.
265 <sect2 renderas="sect3" id="differs"><title>How does Privoxy differ
266 from the old Junkbuster?</title>
268 <application>Privoxy</application> picks up where
269 <application>Junkbuster</application> left off.
270 <application>Privoxy</application> still blocks ads and banners,
272 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>, and still
273 helps protect your privacy. But, most of these features have been enhanced,
274 and many new ones have been added, all in the same vein.
277 <application>Privoxy</application>'s new features include:
280 <!-- Include newfeatures.sgml: -->
286 <sect2 renderas="sect3" id="whatsanad">
287 <title>How does Privoxy know what is an ad, and what is not?</title>
289 <application>Privoxy</application>'s approach to blocking ads is twofold:
292 First, there are certain patterns in the <emphasis>locations</emphasis> (URLs)
293 of banner images. This applies to both the path (you wouldn't guess how many
294 web sites serve their banners from a directory called <quote>banners</quote>!)
295 and the host (blocking the big banner hosting services like doublecklick.net
296 already helps a lot). <application>Privoxy</application> takes advantage of this
297 fact by using <ulink url="../user-manual/actions-file.html#AF-PATTERNS">URL
298 patterns</ulink> to sort out and block the requests for things that sound
299 like they would be ads or banners.
302 Second, banners tend to come in certain <emphasis>sizes</emphasis>. But you
303 can't tell the size of an image by its URL without downloading it, and if you
304 do, it's too late to save bandwidth. Therefore, <application>Privoxy</application>
305 also inspects the HTML sources of web pages while they are loaded, and replaces
306 references to images with standard banner sizes by dummy references, so that
307 your browser doesn't request them anymore in the first place.
310 Both of this involves a certain amount of guesswork and is, of course, freely
311 and readily configurable.
315 <sect2 renderas="sect3" id="mistakes">
316 <title>Can Privoxy make mistakes?
317 This does not sound very scientific.</title>
319 Actually, it's a black art ;-) And yes, it is always possible to have a broad
320 rule accidentally block or change something by mistake. You will almost surely
321 run into such situations at some point. It is tricky writing rules to
322 cover every conceivable possibility, and not occasionally get false positives.
326 But this should not be a big concern since the
327 <application>Privoxy</application> configuration is very flexible, and
328 includes tools to help identify these types of situations so they can be
329 addressed as needed, allowing you to customize your installation.
330 (<link linkend="badsite">See the Troubleshooting section below</link>.)
335 <sect2 renderas="sect3" id="configornot">
336 <title>Will I have to configure Privoxy
337 before I can use it?</title>
339 That depends on your expectations.
340 The default installation should give you a good starting
341 point, and block <emphasis>most</emphasis> ads and unwanted content,
342 but many of the more advanced features are off by default, and require
343 you to activate them.
346 You do have to set up your browser to use
347 <application>Privoxy</application> (see the <link
348 linkend="firststep">Installation section below</link>).
351 And you will certainly run into situations where there are false positives,
352 or ads not being blocked that you may not want to see. In these cases, you
353 would certainly benefit by customizing <application>Privoxy's</application>
354 configuration to more closely match your individual situation. And we
355 encourage you to do this. This is where the real power of
356 <application>Privoxy</application> lies!
361 <sect2 renderas="sect3" id="lan">
362 <title>Can Privoxy run as a server on a network?</title>
364 Yes, &my-app; runs as a server already, and can easily be configured to
365 <quote>serve</quote> more than one client. See <link linkend="lanconfig">
366 How can I set up Privoxy to act as a proxy for my LAN</link> below.
370 <sect2 renderas="sect3" id="browsers2"><title>My browser does the same things as
371 Privoxy. Why should I use Privoxy at all?</title>
373 Modern browsers do indeed have <emphasis>some</emphasis> of the same
374 functionality as <application>Privoxy</application>. Maybe this is
375 adequate for you. But <application>Privoxy</application> is very
376 versatile and powerful, and can probably do a number of things
377 your browser just can't.
380 In addition, a proxy is good choice if you use multiple browsers, or
381 have a LAN with multiple computers since &my-app; can run as a server
382 application. This way all the configuration is in one place, and you don't
383 have to maintain a similar configuration for possibly many browsers or
387 Note, however, that it's recommended to leverage both your browser's
388 and <application>Privoxy's</application> privacy enhancing features
389 at the same time. While your browser probably lacks some features
390 &my-app; offers, it should also be able to do some things more
391 reliably, for example restricting and suppressing JavaScript.
395 <sect2 renderas="sect3" id="whytrust"><title>Why should I trust Privoxy?</title>
397 The most important reason is because you have access to
398 <emphasis>everything</emphasis>, and you can control everything. You can
399 check every line of every configuration file yourself. You can check every
400 last bit of source code should you desire. And even if you can't read code,
401 there should be some comfort in knowing that <!-- thousands of -->other people can,
402 and do read it. You can build the software from scratch, if you want,
403 so that you know the executable is clean, and that it is
404 <emphasis>yours</emphasis>. In fact, we encourage this level of scrutiny. It
405 is one reason we use &my-app; ourselves.
409 <sect2 renderas="sect3" id="license"><title>Is there is a license or fee? What about a
410 warranty? Registration?</title>
412 <application>Privoxy</application> is free software and licensed under the <ulink
413 url="http://www.gnu.org/licenses/old-licenses/gpl-2.0.html">GNU General Public License (GPL) version 2</ulink>.
414 It is free to use, copy, modify or distribute as you wish under the terms of this
415 license. Please see the <link linkend="copyright">Copyright</link> section for more
416 information on the license and copyright. Or the <filename>LICENSE</filename> file
417 that should be included.
420 There is <emphasis>no warranty</emphasis> of any kind, expressed, implied or otherwise.
421 That is something that would cost real money ;-) There is no registration either.
426 <sect2 renderas="sect3" id="spyware">
427 <title>Can Privoxy remove spyware? Adware? Viruses?</title>
429 No, at least not reliably enough to trust it. &my-app; is not designed to be
430 a malware removal tool and the default configuration doesn't even try to
431 filter out any malware.
434 &my-app; could help prevent contact from (known) sites that use such
435 tactics with appropriate configuration rules, and thus could conceivably
436 prevent contamination from such sites. However, keeping such a configuration
437 up to date would require a lot of time and effort that would be better spend
438 on keeping your software itself up to date so it doesn't have known
444 <sect2 renderas="sect3" id="otherads">
445 <title>Can I use Privoxy with other ad-blocking software?</title>
447 &my-app; should work fine with other proxies and other software in general.
450 But it is probably not necessary to use &my-app; in conjunction with other
451 ad-blocking products, and this could conceivably cause undesirable results.
452 It might be better to choose one software or the other and work a little to
453 tweak its configuration to your liking.
456 Note that this is an advice specific to ad blocking.
460 <sect2 renderas="sect3" id="help-the-developers"><title>I would like to help you, what can I do?</title>
462 <sect3 renderas="sect4" id="participate"><title>Would you like to participate?</title>
464 Well, we <emphasis>always</emphasis> need help. There is something for
465 everybody who wants to help us. We welcome new developers, packagers,
466 testers, documentation writers or really anyone with a desire to help in
467 any way. You <emphasis>DO NOT</emphasis> need to be a
468 <quote>programmer</quote>. There are many other tasks available. In fact,
469 the programmers often can't spend as much time programming because of some
470 of the other, more mundane things that need to be done, like checking the
471 Tracker feedback sections or responding to user questions on the mailing
475 So first thing, subscribe to the <ulink
476 url="https://lists.privoxy.org/mailman/listinfo/privoxy-users">Privoxy Users</ulink>
477 or the <ulink url="https://lists.privoxy.org/mailman/listinfo/privoxy-devel">Privoxy
478 Developers</ulink> mailing list, join the discussion, help out other users, provide general
479 feedback or report problems you noticed.
482 If you intend to help out with the trackers, you also might want to <ulink
483 url="https://sourceforge.net/user/registration">get an account on SourceForge.net</ulink>
484 so we don't confuse you with the other name-less users.
487 We also have a <ulink
488 url="../developer-manual/index.html">Developer's Manual</ulink>.
489 While it is partly out of date, it's still worth reading.
492 Our <ulink url="http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup">TODO list</ulink>
493 may be of interest to you as well.
494 Please let us know if you want to work on one of the items listed.
498 <sect3 renderas="sect4" id="donate"><title>Would you like to donate?</title>
500 Donations are welcome. Our
501 <ulink url="http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup">TODO list</ulink>
502 is rather long and being able to pay one (or more) developers to work on Privoxy
503 would make a huge difference, even if it was only for a couple of weeks. Donations may
504 also be used for Privoxy-related travel expenses (for example to attend conferences),
505 for hardware used for Privoxy development and for hosting expenses etc.
509 <application>Privoxy</application> is an associated
510 project of <ulink url="https://www.spi-inc.org/">Software
511 in the Public Interest (SPI)</ulink>, which allows us to receive
512 tax-deductible donations in the United States.
513 You can <ulink url="https://www.spi-inc.org/projects/privoxy/">donate via Paypal</ulink>
514 and <ulink url="https://co.clickandpledge.com/advanced/default.aspx?wid=34115">Click & Pledge</ulink>.
515 For details, please have a look at
516 <ulink url="https://www.spi-inc.org/donations">SPI's general donation page</ulink>.
520 You can also donate to Privoxy using a bank account or a "Paypal" address:
523 Name on account: <ulink url="https://www.zwiebelfreunde.de/">Zwiebelfreunde e.V.</ulink>
524 IBAN: DE95430609671126825604
529 "Paypal" address: privoxy@zwiebelfreunde.de
532 Donations made through Zwiebelfreunde e.V. are tax-deductible in Germany
533 and other countries that recognize German charitable clubs. Feel free to
534 use the Subject field to provide a name to be credited and a list of TODO
535 list items you are interested in the most. For example: Max Mustermann: #16, #1, #14.
539 Note that donations made through Zwiebelfreunde e.V. currently can't be checked
540 automatically so you may not get credited right away. The credits currently
541 reflect donations received before 2016-01-14.
545 If you have any questions regarding donations please mail to either the
546 public user mailing list or, if it's a private matter, to
547 <ulink url="mailto:fk@fabiankeil.de">Fabian Keil</ulink> (Privoxy's SPI liaison)
552 <sect2 id="sponsor"><title>How can I become a sponsor and get my logo or link on privoxy.org?</title>
554 We are currently offering the following sponsor levels as an experiment:
558 <term>Gold (10000 EUR/year)</term>
561 Logo shown at the bottom of the
562 <ulink url="https://www.privoxy.org/">Privoxy homepage</ulink>.
563 Logo, link and self description on the
564 <ulink url="https://www.privoxy.org/sponsors/">sponsor page</ulink>.
569 <term>Silver (1000 EUR/year)</term>
572 Logo shown randomly at the bottom of the
573 <ulink url="https://www.privoxy.org/">Privoxy homepage</ulink>.
574 Logo, link and self description on the
575 <ulink url="https://www.privoxy.org/sponsors/">sponsor page</ulink>.
580 <term>Bronze (500 EUR/year)</term>
583 Logo and link on the <ulink url="https://www.privoxy.org/sponsors/">sponsor page</ulink>.
589 The logo sizes depend on the sponsor level. Logos are served from
590 our server, no requests are made to the sponsor website unless
591 the links are being used.
594 The details may change over time but changes will only affect new sponsors
595 (or existing sponsors that explicitly agreed to the changes).
598 If you want to become a sponsor, please contact
599 <ulink url="mailto:fk@fabiankeil.de">Fabian Keil</ulink>.
600 New sponsors are only accepted if no developer objects.
608 <!-- ~~~~~ New section ~~~~~ -->
610 <sect1 id="installation"><title>Installation</title>
612 <sect2 renderas="sect3" id="whichbrowsers">
613 <title>Which browsers are supported by Privoxy?</title>
615 Any browser that can be configured to use a proxy, which
616 should be virtually all browsers, including
617 <application>Firefox</application>, <application>Internet
618 Explorer</application>, <application>Opera</application>, and
619 <application>Safari</application> among others.
620 Direct browser support is not an absolute requirement since
621 <application>Privoxy</application> runs as a separate application and talks
622 to the browser in the standardized HTTP protocol, just like a web server
627 <sect2 renderas="sect3" id="whichos">
628 <title>Which operating systems are supported?</title>
630 Include supported.sgml here:
635 <sect2 renderas="sect3" id="email-client">
636 <title>Can I use Privoxy with my email client?</title>
638 As long as there is some way to set a HTTP proxy for the client, then yes,
639 any application can be used, whether it is strictly speaking a
640 <quote>browser</quote> or not. Though this may not be the best approach for
641 dealing with some of the common abuses of HTML in email. See <link
642 linkend="outlook">How can I configure <application>Privoxy</application>
643 with <application>Outlook</application>?</link> below for more on
647 Be aware that HTML email presents a number of unique security and privacy
648 related issues, that can require advanced skills to overcome. The developers
649 recommend using email clients that can be configured to convert HTML to plain
650 text for these reasons.
654 <!-- Nobody is going to still be doing this!
655 <sect2 renderas="sect3" id="newinstall"><title>Can I install
656 Privoxy over Junkbuster?</title>
658 We recommend you un-install <application>Junkbuster</application>
659 first to minimize conflicts and confusion. You may want to
660 save your old configuration files for future reference. The configuration
661 files and syntax have substantially changed, so you will need to manually
662 port your old patterns. See the <ulink url="../user-manual/upgradersnote.html">note
663 to upgraders</ulink> and <ulink url="../user-manual/installation.html">installation
664 chapter</ulink> in the <ulink url="../user-manual/index.html">User Manual</ulink>
668 Note: Some installers may automatically un-install
669 <application>Junkbuster</application>, if present!
675 <sect2 renderas="sect3" id="firststep">
676 <title>I just installed Privoxy. Is there anything
677 special I have to do now?</title>
680 All browsers should be told to use <application>Privoxy</application>
681 as a proxy by specifying the correct proxy address and port number
682 in the appropriate configuration area for the browser. It's possible
683 to combine &my-app; with a packet filter to intercept HTTP requests
684 even if the client isn't explicitly configured to use &my-app;,
685 but where possible, configuring the client is recommended. See
686 <ulink url="../user-manual/startup.html">the User Manual for more
687 details</ulink>. You should also flush your browser's memory and disk
688 cache to get rid of any cached junk items, and remove any stored
689 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>.
694 <sect2 renderas="sect3" id="localhost"><title>What is the proxy address of Privoxy?</title>
696 If you set up the <application>Privoxy</application> to run on
697 the computer you browse from (rather than your ISP's server or some
698 networked computer on a LAN), the proxy will be on <literal>127.0.0.1</literal>
699 (sometimes referred to as <quote>localhost</quote>,
700 which is the special name used by every computer on the Internet to refer
701 to itself) and the port will be 8118 (unless you used the <ulink
702 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
703 config option to tell <application>Privoxy</application> to run on
707 When configuring your browser's proxy settings you typically enter
708 the word <quote>localhost</quote> or the IP address <quote>127.0.0.1</quote>
709 in the boxes next to <quote>HTTP</quote> and <quote>Secure</quote> (HTTPS) and
710 then the number <quote>8118</quote> for <quote>port</quote>.
711 This tells your browser to send all web requests to <application>Privoxy</application>
712 instead of directly to the Internet.
715 <application>Privoxy</application> can also be used to proxy for
716 a Local Area Network. In this case, your would enter either the IP
717 address of the LAN host where <application>Privoxy</application>
718 is running, or the equivalent hostname, e.g. <literal>192.168.1.1</literal>.
719 Port assignment would be same as above. Note that
720 <application>Privoxy</application> doesn't listen on any LAN interfaces by
724 <application>Privoxy</application> does not currently handle
725 any other protocols such as FTP, SMTP, IM, IRC, ICQ, etc.
729 <sect2 renderas="sect3" id="nothing">
730 <title>I just installed Privoxy, and nothing is happening.
731 All the ads are there. What's wrong?</title>
734 Did you configure your browser to use <application>Privoxy</application>
735 as a proxy? It does not sound like it. See above. You might also try flushing
736 the browser's caches to force a full re-reading of pages. You can verify
737 that <application>Privoxy</application> is running, and your browser
738 is correctly configured by entering the special URL:
739 <ulink url="http://p.p/">http://p.p/</ulink>.
740 <!-- Use http://p.p/ instead of http://config.privoxy.org/ here because
741 of potential redirect caching problem (see next Q). -->
742 This should take you to a page titled <quote>This is Privoxy..</quote> with
743 access to <application>Privoxy's</application> internal configuration.
744 If you see this, then you are good to go. If you receive a page saying
745 <quote>Privoxy is not running</quote>, then the browser is not set up to use
746 your <application>Privoxy</application> installation.
747 If you receive anything else (probably nothing at all), it could either
748 be that the browser is not set up correctly, or that
749 <application>Privoxy</application> is not running at all. Check the <ulink
750 url="../user-manual/config.html#LOGFILE">log file</ulink>. For instructions
751 on starting <application>Privoxy</application> and browser configuration,
752 see the <ulink url="https://www.privoxy.org/user-manual/startup.html">chapter
753 on starting <application>Privoxy</application></ulink> in the
754 <ulink url="https://www.privoxy.org/user-manual/">User Manual</ulink>.
759 <sect2 renderas="sect3" id="notused">
760 <title>I get a <quote>Privoxy is not being used</quote> dummy page although
761 Privoxy is running and being used.</title>
764 First, make sure that Privoxy is <emphasis>really</emphasis> running and
765 being used by visiting <ulink url="http://p.p/">http://p.p/</ulink>. You
766 should see the <application>Privoxy</application> main page. If not, see
767 the <ulink url="https://www.privoxy.org/user-manual/startup.html">chapter
768 on starting <application>Privoxy</application></ulink> in the
769 <ulink url="https://www.privoxy.org/user-manual/">User Manual</ulink>.
773 Now if <ulink url="http://p.p/">http://p.p/</ulink> works for you, but
774 other parts of <application>Privoxy</application>'s web interface show
775 the dummy page, your browser has cached a redirection it encountered before
776 <application>Privoxy</application> was being used. You need to clear your
777 browser's cache. Note that shift-reloading the dummy page won't help, since
778 that'll only refresh the dummy page, not the redirection that lead you there.
782 The procedure for clearing the cache varies from browser to browser. For
783 example, <application>Mozilla/Netscape</application> users would click
784 <guibutton>Edit</guibutton> --> <guibutton>Preferences</guibutton> -->
785 <guibutton>Advanced</guibutton> --> <guibutton>Cache</guibutton> and
786 then click both <quote><guibutton>Clear Memory Cache</guibutton></quote>
787 and <quote><guibutton>Clear Disk Cache</guibutton></quote>.
788 In some <application>Firefox</application> versions it's
789 <guibutton>Tools</guibutton> --> <guibutton>Options</guibutton> -->
790 <guibutton>Privacy</guibutton> --> <guibutton>Cache</guibutton> and
791 then click <quote><guibutton>Clear Cache Now</guibutton></quote>.
792 <!-- In my Firefox versions it's the Netscape way. fk 2007-11-19-->
799 <!-- ~~~~~ New section ~~~~~ -->
801 <sect1 id="configuration"><title>Configuration</title>
802 <sect2 renderas="sect3" id="actionsfile">
803 <title>What exactly is an <quote>actions</quote> file?</title>
806 &my-app; utilizes the concept of <quote>
807 <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink></quote>
808 that are used to manipulate and control web page data.
809 <ulink url="../user-manual/actions-file.html">Actions files</ulink>
810 are where these <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink>
811 that <application>Privoxy</application> could take while processing a certain
812 request, are configured. Typically, you would define a set of default actions
813 that apply globally to all URLs, then add exceptions to these defaults where needed.
814 There is a wide array of actions available that give the user a high degree
815 of control and flexibility on how to process each and every web page.
819 Actions can be defined on a <ulink
820 url="../user-manual/actions-file.html#AF-PATTERNS">URL pattern</ulink> basis, i.e.
821 for single URLs, whole web sites, groups or parts thereof etc. Actions can also be
822 grouped together and then applied to requests matching one or more patterns.
823 There are many possible actions that might apply to any given site. As an example,
824 if you are blocking <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
825 as one of your default actions, but need to accept cookies from a given site,
826 you would need to define an exception for this site in one of your actions
827 files, preferably in <filename>user.action</filename>.
832 <sect2 renderas="sect3" id="actionss">
833 <title>The <quote>actions</quote> concept confuses me. Please list
834 some of these <quote>actions</quote>.</title>
836 For a comprehensive discussion of the actions concept, please refer
837 to the <ulink url="../user-manual/actions-file.html">actions file
838 chapter</ulink> in the <ulink url="../user-manual/index.html">User
839 Manual</ulink>. It includes a <ulink
840 url="../user-manual/actions-file.html#ACTIONS">list of all actions</ulink>
841 and an <ulink url="../user-manual/actions-file.html#ACT-EXAMPLES">actions
842 file tutorial</ulink> to get you started.
847 <sect2 renderas="sect3" id="actconfig">
848 <title>How are actions files configured? What is the easiest
849 way to do this?</title>
852 Actions files are just text files in a special syntax and can be edited
853 with a text editor. But probably the easiest way is to access
854 <application>Privoxy</application>'s user interface with your web browser
855 at <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
856 (Shortcut: <ulink url="http://p.p/">http://p.p/</ulink>) and then select
857 <quote><ulink url="http://config.privoxy.org/show-status">View &
858 change the current configuration</ulink></quote> from the menu. Note
859 that this feature must be explicitly enabled in the main config file
861 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
866 <sect2 renderas="sect3">
867 <title>There are several different <quote>actions</quote> files. What are
868 the differences?</title>
870 Please have a look at the <ulink url="../user-manual/actions-file.html">the actions chapter</ulink>
871 in the <ulink url="../user-manual/index.html">User Manual</ulink> for a detailed explanation.
876 <sect2 renderas="sect3" id="getupdates"><title>Where can I get updated Actions Files?</title>
878 Based on your feedback and the continuing development, updates of
879 <filename>default.action</filename> will be
880 made available from time to time on the <ulink
881 url="https://sourceforge.net/project/showfiles.php?group_id=11118">files section</ulink> of
882 our <ulink url="https://sourceforge.net/projects/ijbswa/">project page</ulink>.
886 If you wish to receive an email notification whenever we release updates of
887 <application>Privoxy</application> or the actions file, <ulink
888 url="https://lists.privoxy.org/mailman/listinfo/privoxy-announce">subscribe
889 to our announce mailing list</ulink>, privoxy-announce@lists.privoxy.org.
894 <sect2 renderas="sect3" id="newconfig"><title>Can I use my old config files?</title>
896 The syntax and purpose of configuration files has remained roughly the
897 same throughout the 3.x series, but backwards compatibility is not guaranteed.
898 Also each release contains updated, <quote>improved</quote> versions and it is
899 therefore strongly recommended to install the newer configuration files
900 and merge back your modifications.
904 <sect2 renderas="sect3" id="difficult">
905 <title>Why is the configuration so complicated?</title>
907 <quote>Complicated</quote> is in the eye of the beholder.
910 Privoxy is currently mainly written by and for people who are already
911 familiar with the underlying concepts like regular expressions, HTTP and HTML,
912 or are willing to become familiar with them to be able to get the most
913 out of a powerful and flexible tool such as Privoxy.
916 While everybody is expected to be able to get a Privoxy default installation
917 up and running, fine-tuning requires a certain amount of background
918 information and Privoxy's documentation mainly concentrates on the
919 Privoxy-specific parts while only providing references to the rest.
922 If you or anyone you know has the skills, time and energy to
923 reduce the barrier of entry, please <link linkend="participate">get involved</link>.
927 <sect2 renderas="sect3" id="yahoo"><title>How can I make my Yahoo/Hotmail/Gmail account work?</title>
929 The default configuration shouldn't impact the usability of any of these services.
930 It may, however, make all <ulink
931 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
932 temporary, so that your browser will forget your
933 login credentials in between browser sessions. If you would like not to have to log
934 in manually each time you access those websites, simply turn off all cookie handling
935 for them in the <filename>user.action</filename> file. An example for yahoo might
939 <screen># Allow all cookies for Yahoo login:
941 { -<ulink url="../user-manual/actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</ulink> -<ulink url="../user-manual/actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</ulink> -<ulink url="../user-manual/actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</ulink> }
942 .login.yahoo.com</screen>
945 These kinds of sites are often quite complex and heavy with
946 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> and
947 thus <quote>fragile</quote>. So if <emphasis>still</emphasis> a problem,
949 url="../user-manual/actions-file.html#ALIASES">alias</ulink> just for such
953 <screen># Gmail is a _fragile_ site:
955 { <literal>fragile</literal> }
957 mail.google.com</screen>
960 Be sure to flush your browser's caches whenever making these kinds of
961 changes, just to make sure the changes <quote>take</quote>.
964 Make sure the domain, host and path are appropriate as well. Your browser can
965 tell you where you are specifically and you should use that information for
966 your configuration settings. Note that above it is not referenced as
967 <literal>gmail.com</literal>, which is a valid domain name.
972 <sect2 renderas="sect3" id="configfiles"> <title>What's the difference between the
973 <quote>Cautious</quote>, <quote>Medium</quote> and <quote>Advanced</quote> defaults?</title>
975 Configuring <application>Privoxy</application> is not entirely trivial. To
976 help you get started, we provide you with three different default action
977 <quote>profiles</quote> in the web based actions file editor at <ulink
978 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
979 See the <ulink url="../user-manual/actions-file.html"><citetitle>User
980 Manual</citetitle></ulink> for a list of actions, and how the default
985 Where the defaults are likely to break some sites, exceptions for
986 known popular <quote>problem</quote> sites are included, but in
987 general, the more aggressive your default settings are, the more exceptions
988 you will have to make later. New users are best to start off in
989 <quote>Cautious</quote> setting. This is safest and will have the fewest
990 problems. See the <ulink
991 url="../user-manual/index.html"><citetitle>User Manual</citetitle></ulink>
992 for a more detailed discussion.
996 It should be noted that the <quote>Advanced</quote> profile (formerly known
997 as the <quote>Adventuresome</quote> profile) is more
998 aggressive, and will make use of some of
999 <application>Privoxy's</application> advanced features. Use at your own risk!
1004 <sect2 renderas="sect3" id="browseconfig"> <title>Why can I change the configuration
1005 with a browser? Does that not raise security issues?</title>
1007 It may seem strange that regular users can edit the config files with their
1008 browsers, although the whole <filename>/etc/privoxy</filename> hierarchy
1009 belongs to the user <quote>privoxy</quote>, with only 644 permissions.
1012 When you use the browser-based editor, <application>Privoxy</application>
1013 itself is writing to the config files. Because
1014 <application>Privoxy</application> is running as the user <quote>privoxy</quote>,
1015 it can update its own config files.
1018 If you run <application>Privoxy</application> for multiple untrusted users (e.g. in
1019 a LAN) or aren't entirely in control of your own browser, you will probably want
1020 to make sure that the web-based editor and remote toggle features are
1021 <quote>off</quote> by setting <quote><literal><ulink
1022 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>
1023 0</literal></quote> and <quote><literal><ulink
1024 url="../user-manual/config.html#ENABLE-REMOTE-TOGGLE">enable-remote-toggle</ulink>
1025 0</literal></quote> in the <ulink url="../user-manual/config.html">main configuration file</ulink>.
1028 As of &my-app; 3.0.7 these options are disabled by default.
1033 <sect2 renderas="sect3" id="filterfile">
1034 <title>What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>?</title>
1036 The <ulink url="../user-manual/filter-file.html"><filename>default.filter</filename></ulink>
1037 file is where <emphasis>filters</emphasis> as supplied by the developers are defined.
1038 Filters are a special subset of actions that can be used to modify or
1039 remove web page content or headers on the fly. Content filters can
1040 be applied to <emphasis>anything</emphasis> in the page source,
1041 header filters can be applied to either server or client headers.
1042 Regular expressions are used to accomplish this.
1045 There are a number of pre-defined filters to deal with common annoyances. The
1046 filters are only defined here, to invoke them, you need to use the
1048 url="../user-manual/actions-file.html#FILTER"><literal>filter</literal>
1049 action</ulink> in one of the actions files. Content filtering is automatically
1050 disabled for inappropriate MIME types, but if you know better than Privoxy
1051 what should or should not be filtered you can filter any content you like.
1055 <emphasis>not</emphasis> be confused with <ulink
1056 url="../user-manual/actions-file.html#BLOCK"><literal>blocks</literal></ulink>, which
1057 is a completely different action, and is more typically used to block ads and
1062 If you are familiar with regular expressions, and HTML, you can look at
1063 the provided <filename>default.filter</filename> with a text editor and define
1064 your own filters. This is potentially a very powerful feature, but
1065 requires some expertise in both regular expressions and HTML/HTTP.
1066 <![%p-newstuff;[ You should
1067 place any modifications to the default filters, or any new ones you create
1068 in a separate file, such as <filename>user.filter</filename>, so they won't
1069 be overwritten during upgrades.
1070 The ability to define multiple filter files
1071 in <filename>config</filename> is a new feature as of v. 3.0.5.]]>
1075 There is no GUI editor option for this part of the configuration,
1076 but you can disable/enable the various pre-defined filters of the included
1077 <filename>default.filter</filename> file with the <ulink
1078 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1079 Note that the custom actions editor must be explicitly enabled in
1080 the main config file (see <ulink
1081 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
1085 If you intend to develop your own filters, you might want to have a look at
1087 url="https://www.fabiankeil.de/sourcecode/pft/">Privoxy-Filter-Test</ulink>.
1092 <sect2 renderas="sect3" id="lanconfig">
1093 <title>How can I set up Privoxy to act as a proxy for my
1096 By default, <application>Privoxy</application> only responds to requests
1097 from <literal>127.0.0.1</literal> (localhost). To have it act as a server for
1098 a network, this needs to be changed in the <ulink
1099 url="../user-manual/config.html">main configuration file</ulink>. Look for
1101 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink></literal>
1102 option, which may be commented out with a <quote>#</quote> symbol. Make sure
1103 it is uncommented, and assign it the address of the LAN gateway interface,
1104 and port number to use. Assuming your LAN address is 192.168.1.1 and you
1105 wish to run <application>Privoxy</application> on port 8118, this line
1111 listen-address 192.168.1.1:8118</screen>
1115 Save the file, and restart <application>Privoxy</application>. Configure
1116 all browsers on the network then to use this address and port number.
1120 Alternately, you can have <application>Privoxy</application> listen on
1121 all available interfaces:
1126 listen-address :8118</screen>
1130 And then use <application>Privoxy's</application>
1132 url="../user-manual/config.html#PERMIT-ACCESS">permit-access</ulink>
1133 feature to limit connections. A firewall in this situation is recommended
1138 The above steps should be the same for any TCP network, regardless of
1143 If you run <application>Privoxy</application> on a LAN with untrusted users,
1144 we recommend that you double-check the <ulink
1145 url="../user-manual/config.html#ACCESS-CONTROL">access control and security</ulink>
1152 <sect2 renderas="sect3" id="noseeum">
1153 <title>Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
1155 The replacement for blocked images can be controlled with the <ulink
1156 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1157 action</ulink>. You have the choice of a checkerboard pattern, a transparent 1x1 GIF
1158 image (aka <quote>blank</quote>), or a redirect to a custom image of your choice.
1159 Note that this choice only has effect for images which are blocked as images, i.e.
1160 whose URLs match both a <literal><ulink
1161 url="../user-manual/actions-file.html#HANDLE-AS-IMAGE">handle-as-image</ulink></literal>
1162 <emphasis>and</emphasis> <literal><ulink
1163 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> action.
1166 If you want to see nothing, then change the <ulink
1167 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1168 action</ulink> to <quote>blank</quote>. This can be done by editing the
1169 <filename>user.action</filename> file, or through the <ulink
1170 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1175 <sect2 renderas="sect3" id="whyseeum">
1176 <title>Why would anybody want to see a checkerboard pattern?</title>
1178 Remember that <link linkend="whatsanad">telling which image is an ad and which
1179 isn't</link>, is an educated guess. While we hope that the standard configuration
1180 is rather smart, it will make occasional mistakes. The checkerboard image is visually
1181 decent, and it shows you where images have been blocked, which can be very
1182 helpful in case some navigation aid or otherwise innocent image was
1183 erroneously blocked. It is recommended for new users so they can
1184 <quote>see</quote> what is happening. Some people might also enjoy seeing how
1185 many banners they <emphasis>don't</emphasis> have to see.
1190 <sect2 renderas="sect3" id="blockedbytext">
1191 <title>I see some images being replaced with text
1192 instead of the checkerboard image. Why and how do I get rid of this?</title>
1194 This happens when the banners are not embedded in the HTML code of the
1195 page itself, but in separate HTML (sub)documents that are loaded into (i)frames
1196 or (i)layers, and these external HTML documents are blocked. Being non-images
1197 they get replaced by a substitute HTML page rather than a substitute image,
1198 which wouldn't work out technically, since the browser expects and accepts
1199 only HTML when it has requested an HTML document.
1202 The substitute page adapts to the available space and shows itself as a
1203 miniature two-liner if loaded into small frames, or full-blown with a
1204 large red "BLOCKED" banner if space allows.
1207 If you prefer the banners to be blocked by images, you must see to it that
1208 the HTML documents in which they are embedded are not blocked. Clicking
1209 the <quote>See why</quote> link offered in the substitute page will show
1210 you which rule blocked the page. After changing the rule and un-blocking
1211 the HTML documents, the browser will try to load the actual banner images
1212 and the usual image blocking will (hopefully!) kick in.
1217 <sect2 renderas="sect3" id="srvany">
1218 <title>Can Privoxy run as a service
1219 on Win2K/NT/XP?</title>
1222 Yes. Version 3.0.5 introduces full <application>Windows</application> service
1223 functionality. See <ulink url="../user-manual/installation.html#installation-pack-win">
1224 the <citetitle>User Manual</citetitle></ulink> for details on how to install and configure
1225 <application>Privoxy</application> as a service.
1228 Earlier ]]>3.x versions could run as a system service using <command>srvany.exe</command>.
1229 See the discussion at <ulink
1230 url="https://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118">https://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118</ulink>,
1231 for details, and a sample configuration.
1236 <sect2 renderas="sect3" id="otherproxy">
1237 <title>How can I make Privoxy work with other proxies?</title>
1239 This can be done and is often useful to combine the benefits of
1240 <application>Privoxy</application> with those of a another proxy,
1241 for example to cache content.
1243 url="../user-manual/config.html#FORWARDING">forwarding chapter</ulink>
1244 in the <ulink url="../user-manual/index.html">User Manual</ulink> which
1245 describes how to do this. If you intend to use Privoxy with Tor,
1246 please also have a look at
1247 <link linkend="TOR">How do I use Privoxy together with Tor</link>.
1251 <sect2 renderas="sect3" id="port-80">
1252 <title>Can I just set Privoxy to use port 80
1253 and thus avoid individual browser configuration?</title>
1256 No, its more complicated than that. This only works with special kinds
1257 of proxies known as <quote>intercepting</quote> proxies
1258 (<link linkend="INTERCEPTING">see below</link>).
1263 <sect2 renderas="sect3" id="transparent">
1264 <title>Can Privoxy run as a <quote>transparent
1265 </quote> proxy?</title>
1267 The whole idea of Privoxy is to modify client requests
1268 and server responses in all sorts of ways and therefore
1269 it's not a transparent proxy as described in
1270 <ulink url="http://tools.ietf.org/html/rfc2616">RFC 2616</ulink>.
1273 However, some people say <quote>transparent proxy</quote> when they
1274 mean <quote>intercepting proxy</quote>. If you are one of them,
1275 please read the <link linkend="INTERCEPTING">next entry</link>.
1280 <sect2 renderas="sect3" id="intercepting">
1281 <title>Can Privoxy run as a <quote>intercepting</quote> proxy?</title>
1283 <application>Privoxy</application> can't intercept traffic itself,
1284 but it can handle requests that where intercepted and redirected
1285 with a packet filter (like <application>PF</application> or
1286 <application>iptables</application>), as long as the <literal>Host</literal>
1290 As the <literal>Host</literal> header is required by HTTP/1.1 and as most
1291 web sites rely on it anyway, this limitation shouldn't be a problem.
1294 Please refer to your packet filter's documentation to learn how to
1295 intercept and redirect traffic into <application>Privoxy</application>.
1296 Afterward you just have to configure <application>Privoxy</application> to
1297 <ulink url="../user-manual/config.html#ACCEPT-INTERCEPTED-REQUESTS">accept
1298 intercepted requests</ulink>.
1303 <sect2 renderas="sect3" id="outlook">
1304 <title>How can I configure Privoxy for use with Outlook?</title>
1306 Versions of <application>Outlook</application> prior to Office 2007, use
1307 <application>Internet Explorer</application> components to both render HTML,
1308 and fetch any HTTP requests that may be embedded in an HTML email. So however
1309 you have <application>Privoxy</application> configured to work with IE, this
1310 configuration should automatically be shared, at least with older version of
1314 Starting with Office 2007, Microsoft is instead using the MS-Word rendering
1315 engine with Outlook. It is unknown whether this can be configured to use a
1317 <!-- FIXME HB 2009-02-15 -->
1321 <sect2 renderas="sect3" id="outlook-more">
1322 <title>How can I have separate rules just for HTML mail?</title>
1324 The short answer is, you can't. <application>Privoxy</application> has no way
1325 of knowing which particular application makes a request, so there is no way to
1326 distinguish between web pages and HTML mail.
1327 <application>Privoxy</application> just blindly proxies all requests. In the
1328 case of <application>Outlook Express</application> (see above), OE uses
1329 IE anyway, and there is no way for <application>Privoxy</application> to ever
1330 be able to distinguish between them (nor could any other proxy type application for
1334 For a good discussion of some of the issues involved (including privacy and
1335 security issues), see
1336 <ulink url="https://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118">https://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118</ulink>.
1340 <sect2 renderas="sect3" id="sneaky-cookies">
1341 <title>I sometimes notice cookies sneaking through. How?</title>
1344 url="http://en.wikipedia.org/wiki/Browser_cookie">Cookies</ulink> can be
1345 set in several ways. The classic method is via the
1346 <literal>Set-Cookie</literal> HTTP header. This is straightforward, and an
1347 easy one to manipulate, such as the &my-app; concept of
1348 <ulink url="../user-manual/actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</ulink>.
1349 There is also the possibility of using
1350 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> to
1351 set cookies (&my-app; calls these <literal>content-cookies</literal>). This
1352 is trickier because the syntax can vary widely, and thus requires a certain
1353 amount of guesswork. It is not realistic to catch all of these short of
1354 disabling Javascript, which would break many sites. And lastly, if the
1355 cookies are embedded in a HTTPS/SSL secure session via Javascript, they are beyond
1356 <application>Privoxy's</application> reach.
1359 All in all, &my-app; can help manage cookies in general, can help minimize
1360 the loss of privacy posed by cookies, but can't realistically stop all
1365 <sect2 renderas="sect3" id="evil-cookies">
1366 <title>Are all cookies bad? Why?</title>
1368 No, in fact there are many beneficial uses of
1370 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>. Cookies are just a
1371 method that browsers can use to store data between pages, or between browser
1372 sessions. Sometimes there is a good reason for this, and the user's life is a
1373 bit easier as a result. But there is a long history of some websites taking
1374 advantage of this layer of trust, and using the data they glean from you and
1375 your browsing habits for their own purposes, and maybe to your potential
1376 detriment. Such sites are using you and storing their data on your system.
1377 That is why the privacy conscious watch from whom those cookies come, and why
1378 they really <emphasis>need</emphasis> to be there.
1382 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">Wikipedia cookie
1383 definition</ulink> for more.
1387 <sect2 renderas="sect3" id="allow-cookies">
1388 <title>How can I allow permanent cookies for my trusted sites?</title>
1391 There are several actions that relate to cookies. The default behavior is to
1392 allow only <quote>session cookies</quote>, which means the cookies only last
1393 for the current browser session. This eliminates most kinds of abuse related
1394 to cookies. But there may be cases where you want cookies to last.
1397 To disable all cookie actions, so that cookies are allowed unrestricted,
1398 both in and out, for <literal>example.com</literal>:
1402 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
1403 .example.com</screen>
1406 Place the above in <filename>user.action</filename>. Note that some of these may
1407 be off by default anyway, so this might be redundant, but there is no harm
1408 being explicit in what you want to happen. <filename>user.action</filename>
1409 includes an alias for this situation, called
1410 <literal>allow-all-cookies</literal>.
1414 <sect2 renderas="sect3" id="multiples">
1415 <title>Can I have separate configurations for different users?</title>
1417 Each instance of <application>Privoxy</application> has its own
1418 configuration, including such attributes as the TCP port that it listens on.
1419 What you can do is run multiple instances of <application>Privoxy</application>, each with
1421 <ulink url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
1422 configuration setting, and configuration path, and then
1423 each of these can have their own configurations. Think of it as per-port
1427 Simple enough for a few users, but for large installations, consider having
1428 groups of users that might share like configurations.
1432 <sect2 renderas="sect3" id="whitelists">
1433 <title>Can I set-up Privoxy as a whitelist of
1434 <quote>good</quote> sites?</title>
1436 Sure. There are a couple of things you can do for simple white-listing.
1437 Here's one real easy one:
1440 ############################################################
1442 ############################################################
1443 { <ulink url="../user-manual/actions-file.html#BLOCK">+block</ulink> }
1444 / # Block *all* URLs
1446 ############################################################
1448 ############################################################
1449 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1452 games.example.com</screen>
1454 This allows access to only those three sites by first blocking all URLs, and
1455 then subsequently allowing three specific exceptions.
1458 Another approach is <application>Privoxy's</application>
1459 <literal>trustfile</literal> concept, which incorporates the notion of
1460 <quote>trusted referrers</quote>. See the <ulink
1461 url="../user-manual/config.html#TRUSTFILE">Trust documentation</ulink>
1465 These are fairly simple approaches and are not completely foolproof. There
1466 are various other configuration options that should be disabled (described
1467 elsewhere here and in <ulink url="../user-manual/">the User Manual</ulink>)
1468 so that users can't modify their own configuration and easily circumvent the
1473 <sect2 renderas="sect3" id="no-adblock">
1474 <title>How can I turn off ad-blocking?</title>
1476 Ad blocking is achieved through a complex application of various &my-app;
1477 <ulink url="../user-manual/actions-file.html">actions</ulink>. These
1478 actions are deployed against simple images, banners, flash animations,
1479 text pages, JavaScript, pop-ups and pop-unders, etc., so its not as simple as
1480 just turning one or two actions off. The various actions that make up
1481 &my-app; ad blocking are hard-coded into the default configuration files. It
1482 has been assumed that everyone using &my-app; is interested in this
1486 If you want to do without this, there are several approaches you can take:
1487 You can manually undo the many block rules in
1488 <filename>default.action</filename>. Or even easier, just create your own
1489 <filename>default.action</filename> file from scratch without the many ad
1490 blocking rules, and corresponding exceptions. Or lastly, if you are not
1491 concerned about the additional blocks that are done for privacy reasons, you
1492 can very easily over-ride <emphasis>all</emphasis> blocking with the
1493 following very simple rule in your <filename>user.action</filename>:
1497 # Unblock everybody, everywhere
1498 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1499 / # UN-Block *all* URLs</screen>
1502 Or even a more comprehensive reversing of various ad related actions:
1506 # Unblock everybody, everywhere, and turn off appropriate filtering, etc
1507 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> \
1508 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-SIZE">-filter{banners-by-size}</ulink> \
1509 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-LINK">-filter{banners-by-link}</ulink> \
1510 <literal>allow-popups</literal> \
1512 / # UN-Block *all* URLs and allow ads</screen>
1515 This last <quote>action</quote> in this compound statement,
1516 <literal>allow-popups</literal>, is an <ulink
1517 url="../user-manual/actions-file.html#ALIASES">alias</ulink> that disables
1518 various pop-up blocking features.
1522 <sect2 renderas="sect3" id="templates">
1523 <title>How can I have custom template pages, like the
1524 <emphasis>BLOCKED</emphasis> page?</title>
1526 &my-app; <quote>templates</quote> are specialized text files utilized by
1527 &my-app; for various purposes and can easily be modified using any text
1528 editor. All the template pages are installed in a sub-directory appropriately
1529 named: <filename>templates</filename>. Knowing something about HTML syntax
1530 will of course be helpful.
1533 Be forewarned that the default templates are subject to being overwritten
1534 during upgrades. You can, however, create completely new templates,
1535 place them in another directory and specify the alternate path in the main
1536 <filename>config</filename>. For details, have a look at the <ulink
1537 url="../user-manual/config.html#templdir">templdir</ulink> option.
1541 <sect2 renderas="sect3" id="blockall">
1542 <title>How can I remove the <quote>Go There Anyway</quote> link from
1543 the <emphasis>BLOCKED</emphasis> page?</title>
1545 There is more than one way to do it (although Perl is not involved).
1548 Editing the BLOCKED template page (see above) may dissuade some users, but
1549 this method is easily circumvented. Where you need this level of control, you
1550 might want to build &my-app; from source, and disable various features that are
1551 available as compile-time options. You should
1552 <command>configure</command> the sources as follows:
1556 ./configure --disable-toggle --disable-editor --disable-force</screen>
1559 This will create an executable with hard-coded security features so that
1560 &my-app; does not allow easy bypassing of blocked sites, or changing the
1561 current configuration via any connected user's web browser.
1564 Finally, all of these features can also be toggled on/off via options in
1565 <application>Privoxy's</application> main <ulink
1566 url="../user-manual/config.html#ACCESS-CONTROL">config</ulink> file which
1567 means you don't have to recompile anything.
1573 <!-- ~ End section ~ -->
1576 <!-- ~~~~~ New section ~~~~~ -->
1578 <sect1 id="misc"><title>Miscellaneous</title>
1580 <sect2 renderas="sect3" id="slowsme">
1581 <title>How much does Privoxy slow my browsing down? This
1582 has to add extra time to browsing.</title>
1584 How much of an impact depends on many things, including the CPU of the host
1585 system, how aggressive the configuration is, which specific actions are being triggered,
1586 the size of the page, the bandwidth of the connection, etc.
1589 Overall, it should not slow you down any in real terms, and may actually help
1590 speed things up since ads, banners and other junk are not typically being
1591 retrieved and displayed. The actual processing time required by
1592 <application>Privoxy</application> itself for each page, is relatively small
1593 in the overall scheme of things, and happens very quickly. This is typically
1594 more than offset by time saved not downloading and rendering ad images and
1595 other junk content (if ad blocking is being used).
1599 <quote>Filtering</quote> content via the <literal><ulink
1600 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> or
1602 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1603 actions may cause a perceived slowdown, since the entire document
1604 needs to be buffered before displaying. And on very large documents,
1605 filtering may have some measurable impact. How much depends on the page size,
1606 the actual definition of the filter(s), etc. See below. Most other actions
1607 have little to no impact on speed.
1610 Also, when filtering is enabled but zlib support isn't available, compression
1611 is often disabled (see <ulink
1612 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>).
1613 This can have an impact on speed as well, although it's probably smaller than
1614 you might think. Again, the page size, etc. will determine how much of an impact.
1620 <sect2 renderas="sect3" id="loadingtimes"><title>I notice considerable
1621 delays in page requests. What's wrong?</title>
1623 If you use any <literal><ulink
1624 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> action,
1625 such as filtering banners by size, web-bugs etc, or the <literal><ulink
1626 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1627 action, the entire document must be loaded into memory in order for the filtering
1628 mechanism to work, and nothing is sent to the browser during this time.
1631 The loading time typically does not really change much in real numbers, but
1632 the feeling is different, because most browsers are able to start rendering
1633 incomplete content, giving the user a feeling of "it works". This effect is
1634 more noticeable on slower dialup connections. Extremely large documents
1635 may have some impact on the time to load the page where there is filtering
1636 being done. But overall, the difference should be very minimal. If there is a
1637 big impact, then probably some other situation is contributing (like
1638 anti-virus software).
1641 Filtering is automatically disabled for inappropriate MIME types. But note
1642 that if the web server mis-reports the MIME type, then content that should
1643 not be filtered, could be. <application>Privoxy</application> only knows how
1644 to differentiate filterable content because of the MIME type as reported by
1645 the server, or because of some configuration setting that enables/disables
1650 <sect2 renderas="sect3" id="configurl"><title>What are "http://config.privoxy.org/" and
1651 "http://p.p/"?</title>
1653 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink> is the
1654 address of <application>Privoxy</application>'s built-in user interface, and
1655 <ulink url="http://p.p/">http://p.p/</ulink> is a shortcut for it.
1658 Since <application>Privoxy</application> sits between your web browser and the Internet,
1659 it can simply intercept requests for these addresses and answer them with its built-in
1660 <quote>web server</quote>.
1663 This also makes for a good test for your browser configuration: If entering the
1664 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
1665 takes you to a page saying <quote>This is Privoxy ...</quote>, everything is OK.
1666 If you get a page saying <quote>Privoxy is not working</quote> instead, then
1667 your browser didn't use <application>Privoxy</application> for the request,
1668 hence it could not be intercepted, and you have accessed the <emphasis>real</emphasis>
1669 web site at config.privoxy.org.
1672 Note that config.privoxy.org resolves to a public IP address.
1673 If you use config.privoxy.org as ping or traceroute target you will
1674 reach the system on the Internet (Privoxy can't intercept ICMP requests).
1675 If you want to ping the system Privoxy runs on,
1676 you should use its IP address or local DNS name (if it has got one).
1682 out of date 09/02/06 HB
1683 <sect2 renderas="sect3" id="blocklist"><title>Do you still maintain the blocklists?</title>
1685 No. The patterns for blocking now reside (among other things) in the <ulink
1686 url="../user-manual/actions-file.html">actions files</ulink>, which are
1687 actively maintained instead. See next question ...
1691 <sect2 renderas="sect3" id="newads"><title>How can I submit new ads, or report
1694 Please see the <link linkend="contact">Contact section</link> for
1695 various ways to interact with the developers.
1700 <sect2 renderas="sect3" id="newads2"><title>If I do submit missed ads, will
1701 they be included in future updates?</title>
1703 Whether such submissions are eventually included in the
1704 <filename>default.action</filename> configuration file depends on how
1705 significant the issue is. We of course want to address any potential
1706 problem with major, high-profile sites such as <citetitle>Google</citetitle>,
1707 <citetitle>Yahoo</citetitle>, etc. Any site with global or regional reach,
1708 has a good chance of being a candidate. But at the other end of the spectrum
1709 are any number of smaller, low-profile sites such as for local clubs or
1710 schools. Since their reach and impact are much less, they are best handled by
1711 inclusion in the user's <filename>user.action</filename>, and thus would be
1712 unlikely to be included.
1718 <sect2 renderas="sect3" id="noonecares"><title>Why doesn't anyone answer my support
1721 Rest assured that it has been read and considered. Why it is not answered,
1722 could be for various reasons, including no one has a good answer for it, no
1723 one has had time to yet investigate it thoroughly, it has been reported
1724 numerous times already, or because not enough information was provided to help
1725 us help you. Your efforts are not wasted, and we do appreciate them.
1731 <sect2 renderas="sect3" id="ip"><title>How can I hide my IP address?</title>
1733 If you run both the browser and &my-app; locally, you cannot hide your IP
1734 address with <application>Privoxy</application> or ultimately any other
1735 software alone. The server needs to know your IP address so that it knows
1736 where to send the responses back.
1739 There are many publicly usable "anonymous" proxies out there, which
1740 provide a further level of indirection between you and the web server.
1743 However, these proxies are called "anonymous" because you don't need
1744 to authenticate, not because they would offer any real anonymity.
1745 Most of them will log your IP address and make it available to the
1746 authorities in case you violate the law of the country they run in. In fact
1747 you can't even rule out that some of them only exist to *collect* information
1748 on (those suspicious) people with a more than average preference for privacy.
1751 If you want to hide your IP address from most adversaries,
1752 you should consider chaining <application>Privoxy</application>
1753 with <ulink url="https://www.torproject.org/">Tor</ulink>.
1754 The configuration details can be found in
1755 <ulink url="#TOR">How do I use <application>Privoxy</application> together
1756 with <application>Tor</application> section</ulink>
1761 <sect2 renderas="sect3" id="anonforsure">
1762 <title>Can Privoxy guarantee I am anonymous?</title>
1764 No. Your chances of remaining anonymous are improved, but unless you
1765 <ulink url="#TOR">chain <application>Privoxy</application> with <application>Tor</application></ulink>
1766 or a similar proxy and know what you're doing when it comes to configuring
1767 the rest of your system, you should assume that everything you do
1768 on the Web can be traced back to you.
1771 <application>Privoxy</application> can remove various information about you,
1772 and allows <emphasis>you</emphasis> more freedom to decide which sites
1773 you can trust, and what details you want to reveal. But it neither
1774 hides your IP address, nor can it guarantee that the rest of the system
1775 behaves correctly. There are several possibilities how a web sites can find
1776 out who you are, even if you are using a strict <application>Privoxy</application>
1777 configuration and chained it with <application>Tor</application>.
1780 Most of <application>Privoxy's</application> privacy-enhancing features can be easily subverted
1781 by an insecure browser configuration, therefore you should use a browser that can
1782 be configured to only execute code from trusted sites, and be careful which sites you trust.
1783 For example there is no point in having <application>Privoxy</application>
1784 modify the User-Agent header, if websites can get all the information they want
1785 through JavaScript, ActiveX, Flash, Java etc.
1788 A few browsers disclose the user's email address in certain situations, such
1789 as when transferring a file by FTP. <application>Privoxy</application>
1790 does not filter FTP. If you need this feature, or are concerned about the
1791 mail handler of your browser disclosing your email address, you might
1792 consider products such as <application>NSClean</application>.
1795 Browsers available only as binaries could use non-standard headers to give
1796 out any information they can have access to: see the manufacturer's license
1797 agreement. It's impossible to anticipate and prevent every breach of privacy
1798 that might occur. The professionally paranoid prefer browsers available as
1799 source code, because anticipating their behavior is easier. Trust the source,
1805 <sect2 renderas="sect3" id="proxytest">
1806 <title>A test site says I am not using a Proxy.</title>
1808 Good! Actually, they are probably testing for some other kinds of proxies.
1809 Hiding yourself completely would require additional steps.
1813 <sect2 renderas="sect3" id="tor"><title>How do I use Privoxy
1814 together with Tor?</title>
1816 Before you configure <application>Privoxy</application> to use
1817 <ulink url="https://www.torproject.org/">Tor</ulink>,
1818 please follow the <citetitle>User Manual</citetitle> chapters
1819 <ulink url="../user-manual/installation.html">2. Installation</ulink> and
1820 <ulink url="../user-manual/startup.html">5. Startup</ulink> to make sure
1821 <application>Privoxy</application> itself is setup correctly.
1824 If it is, refer to <ulink url="https://www.torproject.org/documentation.html">Tor's
1825 extensive documentation</ulink> to learn how to install <application>Tor</application>,
1826 and make sure <application>Tor</application>'s logfile says that
1827 <quote>Tor has successfully opened a circuit</quote> and it
1828 <quote>looks like client functionality is working</quote>.
1831 If either <application>Tor</application> or <application>Privoxy</application>
1832 isn't working, their combination most likely will neither. Testing them on their
1833 own will also help you to direct problem reports to the right audience.
1834 If <application>Privoxy</application> isn't working, don't bother the
1835 <application>Tor</application> developers. If <application>Tor</application>
1836 isn't working, don't send bug reports to the <application>Privoxy</application> Team.
1839 If you verified that <application>Privoxy</application> and <application>Tor</application>
1840 are working, it is time to connect them. As far as <application>Privoxy</application>
1841 is concerned, <application>Tor</application> is just another proxy that can be reached
1842 by socks4, socks4a and socks5. Most likely you are interested in <application>Tor</application>
1843 to increase your anonymity level, therefore you should use socks5, to make sure DNS
1844 requests are done through <application>Tor</application> and thus invisible to your
1845 local network. Using socks4a would work too, but with socks5 you get more precise error
1850 <application>Privoxy's</application>
1851 <ulink url="../user-manual/config.html">main configuration file</ulink>
1852 is already prepared for <application>Tor</application>, if you are using a
1853 default <application>Tor</application> configuration and run it on the same
1854 system as &my-app;, you just have to edit the
1855 <ulink url="../user-manual/config.html#FORWARDING">forwarding section</ulink>
1856 and uncomment the line:
1860 # forward-socks5t / 127.0.0.1:9050 .
1864 Note that if you got Tor through one of the bundles, you may
1865 have to change the port from 9050 to 9150 (or even another one).
1866 For details, please check the documentation on the
1867 <ulink url="https://torproject.org/">Tor website</ulink>.
1871 This is enough to reach the Internet, but additionally you might want to
1872 uncomment the following forward rules, to make sure your local network is still
1873 reachable through Privoxy:
1877 # forward 192.168.*.*/ .
1878 # forward 10.*.*.*/ .
1879 # forward 127.*.*.*/ .
1883 Unencrypted connections to systems in these address ranges will
1884 be as (un)secure as the local network is, but the alternative is
1885 that your browser can't reach the network at all. Then again,
1886 that may actually be desired and if you don't know for sure
1887 that your browser has to be able to reach the local network,
1888 there's no reason to allow it.
1891 If you want your browser to be able to reach servers in your local
1892 network by using their names, you will need additional exceptions
1893 that look like this:
1897 # forward localhost/ .
1901 Save the modified configuration file and open
1902 <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1903 in your browser, confirm that <application>Privoxy</application> has reloaded its configuration
1904 and that there are no other forward lines, unless you know that you need them. If everything looks good,
1906 <ulink url="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#IsMyConnectionPrivate">Tor
1907 Faq 4.2</ulink> to learn how to verify that you are really using <application>Tor</application>.
1910 Afterward, please take the time to at least skim through the rest
1911 of <application>Tor's</application> documentation. Make sure you understand
1912 what <application>Tor</application> does, why it is no replacement for
1913 application level security, and why you probably don't want to
1914 use it for unencrypted logins.
1918 <sect2 renderas="sect3" id="sitebreak">
1919 <title>Might some things break because header information or
1920 content is being altered?</title>
1923 Definitely. It is common for sites to use browser type, browser version,
1924 HTTP header content, and various other techniques in order to dynamically
1925 decide what to display and how to display it. What you see, and what I see,
1926 might be very different. There are many, many ways that this can be handled,
1927 so having hard and fast rules, is tricky.
1931 The <quote>User-Agent</quote> is sometimes used in this way to identify
1932 the browser, and adjust content accordingly.
1936 Also, different browsers use different encodings of non-English
1937 characters, certain web servers convert pages on-the-fly according to the
1938 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1939 operating system or browser manufacturer causes some sites in these languages
1940 to be garbled; Surfers to Eastern European sites should change it to
1941 something closer. And then some page access counters work by looking at the
1942 <quote>Referer</quote> header; they may fail or break if unavailable. The
1943 weather maps of Intellicast have been blocked by their server when no
1944 <quote>Referer</quote> or cookie is provided, is another example. (But you
1945 can forge both headers without giving information away). There are
1946 many other ways things can go wrong when trying to fool a web server. The
1947 results of which could inadvertently cause pages to load incorrectly,
1948 partially, or even not at all. And there may be no obvious clues as to just
1949 what went wrong, or why. Nowhere will there be a message that says
1950 <quote><emphasis>Turn off <literal>fast-redirects</literal> or else!</emphasis>
1955 Similar thoughts apply to modifying JavaScript, and, to a lesser degree,
1960 If you have problems with a site, you will have to adjust your configuration
1961 accordingly. Cookies are probably the most likely adjustment that may
1962 be required, but by no means the only one.
1968 <sect2 renderas="sect3" id="caching">
1969 <title>Can Privoxy act as a <quote>caching</quote> proxy to
1970 speed up web browsing?</title>
1972 No, it does not have this ability at all. You want something like
1973 <ulink url="http://www.squid-cache.org/">Squid</ulink> or
1974 <ulink url="http://www.pps.jussieu.fr/~jch/software/polipo/">Polipo</ulink> for this.
1975 And, yes, before you ask, <application>Privoxy</application> can co-exist
1976 with other kinds of proxies like <application>Squid</application>.
1977 See the <ulink url="../user-manual/config.html#FORWARDING">forwarding
1978 chapter</ulink> in the <ulink url="../user-manual/index.html">user
1979 manual</ulink> for details.
1983 <sect2 renderas="sect3" id="firewall">
1984 <title>What about as a firewall? Can Privoxy protect me?</title>
1986 Not in the way you mean, or in the way some firewall vendors claim they can.
1987 <application>Privoxy</application> can help protect your privacy, but can't
1988 protect your system from intrusion attempts. It is, of course, perfectly possible
1989 to use <emphasis>both</emphasis>.
1993 <sect2 renderas="sect3" id="wasted">
1994 <title>I have large empty spaces / a checkerboard pattern now where
1995 ads used to be. Why?</title>
1997 It is technically possible to eliminate banners and ads in a way that frees
1998 their allocated page space. This could easily be done by blocking with
1999 <application>Privoxy's</application> filters,
2000 and eliminating the <emphasis>entire</emphasis> image references from the
2004 But, this would consume considerably more CPU resources (IOW, slow things
2005 down), would likely destroy the layout of some web pages which rely on the
2006 banners utilizing a certain amount of page space, and might fail in other
2007 cases, where the screen space is reserved (e.g. by HTML tables for instance).
2008 Also, making ads and banners disappear without any trace complicates
2009 troubleshooting, and would sooner or later be problematic.
2012 The better alternative is to instead let them stay, and block the resulting
2013 requests for the banners themselves as is now the case. This leaves either
2014 empty space, or the familiar checkerboard pattern.
2017 So the developers won't support this in the default configuration, but you
2018 can of course define appropriate filters yourself to achieve this.
2022 <sect2 renderas="sect3" id="ssl">
2023 <title>How can Privoxy filter Secure (HTTPS) URLs?</title>
2025 Since secure HTTP connections are encrypted SSL sessions between your browser
2026 and the secure site, and are meant to be reliably <emphasis>secure</emphasis>,
2027 there is little that <application>Privoxy</application> can do but hand the raw
2028 gibberish data though from one end to the other unprocessed.
2031 The only exception to this is blocking by host patterns, as the client needs
2032 to tell <application>Privoxy</application> the name of the remote server,
2033 so that <application>Privoxy</application> can establish the connection.
2034 If that name matches a host-only pattern, the connection will be blocked.
2037 As far as ad blocking is concerned, this is less of a restriction than it may
2038 seem, since ad sources are often identifiable by the host name, and often
2039 the banners to be placed in an encrypted page come unencrypted nonetheless
2040 for efficiency reasons, which exposes them to the full power of
2041 <application>Privoxy</application>'s ad blocking.
2044 <quote>Content cookies</quote> (those that are embedded in the actual HTML or
2045 JS page content, see <literal><ulink
2046 url="../user-manual/actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</ulink></literal>),
2047 in an SSL transaction will be impossible to block under these conditions.
2048 Fortunately, this does not seem to be a very common scenario since most
2049 cookies come by traditional means.
2054 <sect2 renderas="sect3" id="http2">
2055 <title>Does Privoxy support HTTP/2?</title>
2057 Privoxy currently doesn't parse HTTP/2 but applications
2058 can tunnel HTTP/2 through Privoxy if Privoxy is configured
2059 to allow CONNECT requests (default) which are also used
2063 Adding HTTP/2 support is on the TODO list but currently
2064 nobody is known to work on it.
2068 <sect2 renderas="sect3" id="secure">
2069 <title>Privoxy runs as a <quote>server</quote>. How
2070 secure is it? Do I need to take any special precautions?</title>
2072 On Unix-like systems, <application>Privoxy</application> can run as a non-privileged
2073 user, which is how we recommend it be run. Also, by default
2074 <application>Privoxy</application> listens to requests from <quote>localhost</quote>
2078 The server aspect of <application>Privoxy</application> is not itself directly
2079 exposed to the Internet in this configuration. If you want to have
2080 <application>Privoxy</application> serve as a LAN proxy, this will have to
2081 be opened up to allow for LAN requests. In this case, we'd recommend
2082 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
2083 <application>Privoxy</application> configuration file and check all <ulink
2084 url="../user-manual/config.html#ACCESS-CONTROL">access control and security
2085 options</ulink>. All LAN hosts can then use this as their proxy address
2086 in the browser proxy configuration, but <application>Privoxy</application>
2087 will not listen on any external interfaces. ACLs can be defined in addition,
2088 and using a firewall is always good too. Better safe than sorry.
2093 <sect2 renderas="sect3" id="turnoff">
2094 <title>Can I temporarily disable Privoxy?</title>
2096 &my-app; doesn't have a transparent proxy mode,
2097 but you can toggle off blocking and content filtering.
2100 The easiest way to do that is to point your browser
2101 to the remote toggle URL: <ulink
2102 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>.
2105 See the <ulink url="../user-manual/appendix.html#BOOKMARKLETS">Bookmarklets section</ulink>
2106 of the <citetitle>User Manual</citetitle> for an easy way to access this
2107 feature. Note that this is a feature that may need to be enabled in the main
2108 <filename>config</filename> file.
2113 <sect2 renderas="sect3" id="reallyoff">
2114 <title>When <quote>disabled</quote> is Privoxy totally
2115 out of the picture?</title>
2117 No, this just means all optional filtering and actions are disabled.
2118 <application>Privoxy</application> is still acting as a proxy, but just
2119 doing less of the things that <application>Privoxy</application> would
2120 normally be expected to do. It is still a <quote>middle-man</quote> in
2121 the interaction between your browser and web sites. See below to bypass
2126 <sect2 renderas="sect3" id="turnoff2">
2127 <title>How can I tell Privoxy to totally ignore certain sites?</title>
2129 Bypassing a proxy, or proxying based on arbitrary criteria, is purely a browser
2130 configuration issue, not a &my-app; issue. Modern browsers typically do have
2131 settings for not proxying certain sites. Check your browser's help files.
2136 <sect2 renderas="sect3" id="crunch">
2137 <title>My logs show Privoxy <quote>crunches</quote>
2138 ads, but also its own internal CGI pages. What is a <quote>crunch</quote>?</title>
2140 A <quote>crunch</quote> means <application>Privoxy</application> intercepted
2141 <emphasis>something</emphasis>, nothing more. Often this is indeed ads or
2142 banners, but <application>Privoxy</application> uses the same mechanism for
2143 trapping requests for its own internal pages. For instance, a request for
2144 <application>Privoxy's</application> configuration page at: <ulink
2145 url="http://config.privoxy.org">http://config.privoxy.org</ulink>, is
2146 intercepted (i.e. it does not go out to the 'net), and the familiar CGI
2147 configuration is returned to the browser, and the log consequently will show
2148 a <quote>crunch</quote>.
2151 Since version 3.0.7, Privoxy will also log the crunch reason.
2152 If you are using an older version you might want to upgrade.
2156 <sect2 renderas="sect3" id="downloads">
2157 <title>Can Privoxy affect files that I download
2158 from a webserver? FTP server?</title>
2160 From the webserver's perspective, there is no difference between
2161 viewing a document (i.e. a page), and downloading a file. The same is true of
2162 <application>Privoxy</application>. If there is a match for a <literal><ulink
2163 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> pattern,
2164 it will still be blocked, and of course this is obvious.
2167 Filtering is potentially more of a concern since the results are not always
2168 so obvious, and the effects of filtering are there whether the file is simply
2169 viewed, or downloaded. And potentially whether the content is some obnoxious
2170 advertisement, or Mr. Jimmy's latest/greatest source code jewel. Of course,
2171 one of these presumably is <quote>bad</quote> content that we don't want, and
2172 the other is <quote>good</quote> content that we do want.
2173 <application>Privoxy</application> is blind to the differences, and can only
2174 distinguish <quote>good from bad</quote> by the configuration parameters
2175 <emphasis>we</emphasis> give it.
2178 <application>Privoxy</application> knows the differences in files according
2179 to the <quote>Content Type</quote> as reported by the webserver. If this is
2180 reported accurately (e.g. <quote>application/zip</quote> for a zip archive),
2181 then <application>Privoxy</application> knows to ignore these where
2182 appropriate. <application>Privoxy</application> potentially can filter HTML
2183 as well as plain text documents, subject to configuration parameters of
2184 course. Also, documents that are of an unknown type (generally assumed to be
2185 <quote>text/plain</quote>) can be filtered, as will those that might be
2186 incorrectly reported by the webserver. If such a file is a downloaded file
2187 that is intended to be saved to disk, then any content that might have been
2188 altered by filtering, will be saved too, for these (probably rare) cases.
2191 Note that versions later than 3.0.2 do NOT filter document types reported as
2192 <quote>text/plain</quote>. Prior to this, <application>Privoxy</application>
2193 did filter this document type.
2196 In short, filtering is <quote>ON</quote> if a) the content type as reported
2197 by the webserver is appropriate <emphasis>and</emphasis> b) the configuration
2198 allows it (or at least does not disallow it). That's it. There is no magic
2199 cookie anywhere to say this is <quote>good</quote> and this is
2200 <quote>bad</quote>. It's the configuration that lets it all happen or not.
2203 If you download text files, you probably do not want these to be filtered,
2204 particularly if the content is source code, or other critical content. Source
2205 code sometimes might be mistaken for Javascript (i.e. the kind that might
2206 open a pop-up window). It is recommended to turn off filtering for download
2207 sites (particularly if the content may be plain text files and you are using
2208 version 3.0.2 or earlier) in your <filename>user.action</filename> file. And
2209 also, for any site or page where making <emphasis>any</emphasis> changes at
2210 all to the content is to be avoided.
2213 <application>Privoxy</application> does not do FTP at all, only HTTP
2214 and HTTPS (SSL) protocols.
2218 <sect2 renderas="sect3" id="downloads2">
2219 <title>I just downloaded a Perl script, and Privoxy
2220 altered it! Yikes, what is wrong!</title>
2226 <sect2 renderas="sect3" id="hostsfile">
2227 <title>Should I continue to use a <quote>HOSTS</quote> file for ad-blocking?</title>
2229 One time-tested technique to defeat common ads is to trick the local DNS
2230 system by giving a phony IP address for the ad generator in the local
2231 <filename>HOSTS</filename> file, typically using <literal>127.0.0.1</literal>, aka
2232 <literal>localhost</literal>. This effectively blocks the ad.
2235 There is no reason to use this technique in conjunction with
2236 <application>Privoxy</application>. <application>Privoxy</application>
2237 does essentially the same thing, much more elegantly and with much more
2238 flexibility. A large <filename>HOSTS</filename> file, in fact, not only
2239 duplicates effort, but may get in the way and seriously slow down your system.
2240 It is recommended to remove such entries from your <filename>HOSTS</filename> file. If you think
2241 your hosts list is neglected by <application>Privoxy's </application>
2242 configuration, consider adding your list to your <filename>user.action</filename> file:
2249 ads.galore.example.com
2250 etc.example.com</screen>
2254 <sect2 renderas="sect3" id="seealso">
2255 <title>Where can I find more information about Privoxy
2256 and related issues?</title>
2257 <!-- Include seealso.sgml boilerplate: -->
2259 <!-- end boilerplate -->
2264 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
2270 <sect2 renderas="sect3" id="microsuck">
2271 <title>I've noticed that Privoxy changes <quote>Microsoft</quote> to
2272 <quote>MicroSuck</quote>! Why are you manipulating my browsing?</title>
2275 We're not. The text substitutions that you are seeing are disabled
2276 in the default configuration as shipped. You have either manually
2277 activated the <quote><literal>fun</literal></quote> filter which
2278 is clearly labeled <quote>Text replacements for subversive browsing
2279 fun!</quote> or you are using an older Privoxy version and have implicitly
2280 activated it by choosing the <quote>Advanced</quote> profile in the
2281 web-based editor. Please upgrade.
2285 <sect2 renderas="sect3" id="valid">
2286 <title>Does Privoxy produce <quote>valid</quote> HTML (or XHTML)?</title>
2289 Privoxy generates HTML in both its own <quote>templates</quote>, and possibly
2290 whenever there are text substitutions via a &my-app; filter. While this
2291 should always conform to the HTML 4.01 specifications, it has not been
2292 validated against this or any other standard.
2296 <sect2 renderas="sect3" id="surprise-privoxy">
2297 <title>How did you manage to get Privoxy on my computer without my consent?</title>
2300 We didn't. We make Privoxy available for download, but we don't go
2301 around installing it on other people's systems behind their back.
2302 If you discover Privoxy running on your system and are sure you didn't
2303 install it yourself, somebody else did. You may not even be running
2304 the real Privoxy, but maybe something else that only pretends to be
2305 Privoxy, or maybe something that is based on the real Privoxy,
2306 but has been modified.
2309 Lately there have been reports of problems with some kind of
2310 "parental control" software based on Privoxy that came preinstalled on
2311 certain <ulink url="https://sourceforge.net/p/ijbswa/bugs/813/">ASUS Netbooks</ulink>.
2312 The problems described are inconsistent with the behaviour of official
2313 Privoxy versions, which suggests that the preinstalled software may
2314 contain vendor modifications that we don't know about and thus can't debug.
2317 Privoxy's <link linkend="copyright">license</link> allows vendor
2318 modifications, but the vendor has to comply with the license,
2319 which involves informing the user about the changes and to make
2320 the changes available under the same license as Privoxy itself.
2323 If you are having trouble with a modified Privoxy version,
2324 please try to talk to whoever made the modifications before
2325 reporting the problem to us. Please also try to convince
2326 whoever made the modifications to talk to us. If you think
2327 somebody gave you a modified Privoxy version without complying
2328 to the license, please let us know.
2336 <!-- ~~~~~ New section ~~~~~ -->
2338 <sect1 id="trouble">
2339 <title>Troubleshooting</title>
2341 <sect2 renderas="sect3" id="refused">
2342 <title>I cannot connect to any websites. Or, I am getting
2343 <quote>connection refused</quote> message with every web page. Why?</title>
2345 There are several possibilities:
2350 <application>Privoxy</application> is not running. Solution: verify
2351 that &my-app; is installed correctly, has not crashed, and is indeed running.
2352 Turn on <application>Privoxy's</application> logging, and look at the logs to see what they say.
2354 <listitem><para>Or your browser is configured for a different port than what
2355 <application>Privoxy</application> is using. Solution: verify that &my-app;
2356 and your browser are set to the same port (<literal>listen-address</literal>).
2358 <listitem><para>Or if using a forwarding rule, you have a configuration problem or a
2359 problem with a host in the forwarding chain. Solution: temporarily alter your
2360 configuration and take the forwarders out of the equation.
2363 Or you have a firewall that is interfering and blocking you. Solution:
2364 try disabling or removing the firewall as a simple test.
2371 <!-- ~~~~~ New section ~~~~~ -->
2372 <sect2 renderas="sect3" id="error503">
2373 <title>Why am I getting a 503 Error (WSAECONNREFUSED) on every page?</title>
2375 More than likely this is a problem with your TCP/IP networking. ZoneAlarm has
2376 been reported to cause this symptom -- even if not running! The solution is
2377 to either fight the ZA configuration, or uninstall ZoneAlarm, and then find
2378 something better behaved in its place. Other personal firewall type products
2379 may cause similar type problems if not configured correctly.
2383 <sect2 renderas="sect3" id="flushit">
2384 <title>I just added a new rule, but the steenkin ad is
2385 still getting through. How?</title>
2387 If the ad had been displayed before you added its URL, it will probably be
2388 held in the browser's cache for some time, so it will be displayed without
2389 the need for any request to the server, and <application>Privoxy</application>
2390 will not be involved. Flush the browser's caches, and then try again.
2394 If this doesn't help, you probably have an error in the rule you
2395 applied. Try pasting the full URL of the offending ad into <ulink
2396 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2397 and see if it really matches your new rule. Blocking ads is like blocking
2398 spam: a lot of tinkering is required to stay ahead of the game. And
2399 remember you need to block the URL of the ad in question, which may be
2400 entirely different from the site URL itself. Most ads are hosted on different
2401 servers than the main site itself. If you right-click on the ad, you should
2402 be able to get all the relevant information you need. Alternately, you can
2403 find the correct URL by looking at <application>Privoxy's</application> logs
2404 (you may need to enable logging in the main config file if its disabled).
2407 Below is a slightly modified real-life log snippet that originates with one
2408 requested URL: <literal>www.example.com</literal> (name of site was changed
2409 for this example, the number of requests is real). You can see in this the
2410 complexity of what goes into making up this one <quote>page</quote>. There
2411 are eight different domains involved here, with thirty two separate URLs
2412 requested in all, making up all manner of images, Shockwave Flash,
2413 JavaScript, CSS stylesheets, scripts, and other related content. Some of this
2414 content is obviously <quote>good</quote> or <quote>bad</quote>, but not all.
2415 Many of the more questionable looking requests, are going to outside domains
2416 that seem to be identifying themselves with suspicious looking names, making
2417 our job a little easier. &my-app; has <quote>crunched</quote> (meaning caught
2418 and BLOCKED) quite a few items in this example, but perhaps missed a few as well.
2423 Request: www.example.com/
2424 Request: www.example.com/favicon.ico
2425 Request: img.example.com/main.css
2426 Request: img.example.com/sr.js
2427 Request: example.betamarker.com/example.html
2428 Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
2429 Request: img.example.com/pb.png
2430 Request: www.google-analytics.com/urchin.js crunch! (Blocked)
2431 Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch! (Blocked)
2432 Request: img.example.com/p.gif
2433 Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch! (Blocked)
2434 Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch! (Blocked)
2435 Request: www.popuptraffic.com/assign.php?l=example crunch! (Blocked)
2436 Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
2437 Request: www.adtrak.net/adx.js crunch! (Blocked)
2438 Request: img.example.com/hbg.gif
2439 Request: img.example.com/example.jpg
2440 Request: img.example.com/mt.png
2441 Request: img.example.com/mm.png
2442 Request: img.example.com/mb.png
2443 Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch! (Blocked)
2444 Request: www.example.com/tracker.js
2445 Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
2446 Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch! (Blocked)
2447 Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch! (Blocked)
2448 Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
2449 Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch! (Blocked)
2450 Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
2451 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch! (Blocked)
2452 Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
2453 Request: 66.70.21.80/img/pixel.gif
2454 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch! (Blocked)
2455 Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
2460 Despite 12 out of 32 requests being blocked, the page looked, and seemed to
2461 behave perfectly <quote>normal</quote> (minus some ads, of course).
2466 <sect2 renderas="sect3" id="badsite">
2467 <title>One of my favorite sites does not work with Privoxy.
2468 What can I do?</title>
2471 First verify that it is indeed a <application>Privoxy</application> problem,
2472 by toggling off <application>Privoxy</application> through <ulink
2473 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
2474 (the toggle feature may need to be enabled in the main
2475 <filename>config</filename>),
2476 and then shift-reloading the problem page (i.e. holding down the shift key
2477 while clicking reload. Alternatively, flush your browser's disk and memory
2482 If the problem went away, we know we have a configuration related problem.
2484 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2485 and paste the full URL of the page in question into the prompt. See which
2486 actions are being applied to the URL, and which matches in which actions
2487 files are responsible for that. It might be helpful also to look at your logs
2488 for this site too, to see what else might be happening (note: logging may need
2489 to be enabled in the main config file). Many sites are
2490 complex and require a number of related pages to help present their content.
2491 Look at what else might be used by the page in question, and what of that
2492 might be <emphasis>required</emphasis>.
2493 Now, armed with this information, go to
2495 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2496 and select the appropriate actions files for editing. </para>
2498 You can now either look for a section which disables the actions that
2499 you suspect to cause the problem and add a pattern for your site there,
2500 or make up a completely new section for your site. In any case, the recommended
2501 way is to disable only the prime suspect, reload the problem page, and only
2502 if the problem persists, disable more and more actions until you have
2503 identified the culprit. You may or may not want to turn the other actions
2504 on again. Remember to flush your browser's caches in between any such changes!
2507 Alternately, if you are comfortable with a text editor, you can accomplish
2508 the same thing by editing the appropriate actions file. Probably the easiest
2509 way to deal with such problems when editing by hand is to add your
2510 site to a <literal>{ fragile }</literal> section in <filename>user.action</filename>,
2511 which is an alias that turns off most <quote>dangerous</quote>
2512 actions, but is also likely to turn off more actions then needed, and thus lower
2513 your privacy and protection more than necessary,
2516 Troubleshooting actions is discussed in more detail in the <ulink
2517 url="../user-manual/appendix.html#ACTIONSANAT">User Manual appendix,
2518 Troubleshooting: the Anatomy of an Action</ulink>.
2519 There is also an <ulink
2520 url="../user-manual/actions-file.html#ACT-EXAMPLES">actions tutorial</ulink>
2521 with general configuration information and examples.
2524 As a last resort, you can always see if your browser has a setting that will
2525 bypass the proxy setting for selective sites. Modern browsers can do this.
2531 <!-- ~~~~~ New section ~~~~~ -->
2532 <sect2 id="dun" renderas="sect3">
2533 <title>After installing Privoxy, I have to log in
2534 every time I start IE. What gives?</title>
2537 This is a quirk that affects the installation of
2538 <application>Privoxy</application>, in conjunction with Internet Explorer and
2539 Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may
2540 appear to be corrupted or invalid DUN settings, or passwords.
2544 When setting up an NT based Windows system with
2545 <application>Privoxy</application> you may find that things do not seem to be
2546 doing what you expect. When you set your system up you will probably have set
2547 up Internet Connection Sharing (ICS) with Dial up Networking (DUN) when
2548 logged in with administrator privileges. You will probably have made this DUN
2549 connection available to other accounts that you may have set-up on your
2550 system. E.g. Mum or Dad sets up the system and makes accounts suitably
2551 configured for the kids.
2555 When setting up <application>Privoxy</application> in this environment you
2556 will have to alter the proxy set-up of Internet Explorer (IE) for the
2557 specific DUN connection on which you wish to use
2558 <application>Privoxy</application>. When you do this the ICS DUN set-up
2559 becomes user specific. In this instance you will see no difference if you
2560 change the DUN connection under the account used to set-up the connection.
2561 However when you do this from another user you will notice that the DUN
2562 connection changes to make available to "Me only". You will also find that
2563 you have to store the password under each different user!
2567 The reason for this is that each user's set-up for IE is user specific. Each
2568 set-up DUN connection and each LAN connection in IE store the settings for
2569 each user individually. As such this enforces individual configurations
2570 rather than common ones. Hence the first time you use a DUN connection after
2571 re-booting your system it may not perform as you expect, and prompt you for
2572 the password. Just set and save the password again and all should be OK.
2576 [Thanks to Ray Griffith for this submission.]
2581 <!-- ~~~~~ New section ~~~~~ -->
2582 <sect2 id="ftp" renderas="sect3">
2583 <title>I cannot connect to any FTP sites. Privoxy
2584 is blocking me.</title>
2586 <application>Privoxy</application> cannot act as a proxy for FTP traffic,
2587 so do not configure your browser to use <application>Privoxy</application>
2588 as an FTP proxy. The same is true for <emphasis>any protocol other than HTTP
2589 or HTTPS (SSL)</emphasis>.
2592 Most browsers understand FTP as well as HTTP. If you connect to a site, with
2593 a URL like <literal>ftp://ftp.example.com</literal>, your browser is making
2594 an FTP connection, and not a HTTP connection. So while your browser may
2595 speak FTP, <application>Privoxy</application> does not, and cannot proxy
2599 To complicate matters, some systems may have a generic <quote>proxy</quote>
2600 setting, which will enable various protocols, including
2601 <emphasis>both</emphasis> HTTP and FTP proxying! So it is possible to
2602 accidentally enable FTP proxying in these cases. And of course, if this
2603 happens, <application>Privoxy</application> will indeed cause problems since
2604 it does not know FTP. <![%p-newstuff;[Newer version will give a sane error
2605 message if a FTP connection is attempted.]]> Just disable the FTP setting
2606 and all will be well again.
2609 Will <application>Privoxy</application> ever proxy FTP traffic? Unlikely.
2610 There just is not much reason, and the work to make this happen is more than
2615 <!-- ~~~~~ New section ~~~~~ -->
2616 <sect2 id="macosxie" renderas="sect3">
2617 <title>In Mac OS X, I can't configure Microsoft Internet Explorer to use
2618 Privoxy as the HTTP proxy.</title>
2620 Microsoft Internet Explorer (in versions like 5.1) respects system-wide
2621 network settings. In order to change the HTTP proxy, open System
2622 Preferences, and click on the Network icon. In the settings pane that
2623 comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox
2624 is checked and enter <literal>127.0.0.1</literal> in the entry field.
2625 Enter <literal>8118</literal> in the Port field. The next time you start
2626 IE, it should reflect these values.
2630 <!-- ~~~~~ New section ~~~~~ -->
2631 <sect2 renderas="sect3" id="macosxuninstall">
2632 <title>In Mac OS X, I dragged the Privoxy folder to the trash in order to
2633 uninstall it. Now the finder tells me I don't have sufficient privileges to
2634 empty the trash.</title>
2636 Note: This ONLY applies to privoxy 3.0.6 and earlier.
2639 Just dragging the <application>Privoxy</application> folder to the trash is
2640 not enough to delete it. <application>Privoxy</application> supplies an
2641 <application>uninstall.command</application> file that takes care of
2642 these details. Open the trash, drag the <application>uninstall.command</application>
2643 file out of the trash and double-click on it. You will be prompted for
2644 confirmation and the administration password.
2647 The trash may still appear full after this command; emptying the trash
2648 from the desktop should make it appear empty again.
2652 <!-- ~~~~~ New section ~~~~~ -->
2653 <sect2 renderas="sect3" id="macosximages">
2654 <title>In Mac OS X Panther (10.3), images often fail to load and/or I
2655 experience random delays in page loading. I'm using
2656 <literal>localhost</literal> as my browser's proxy setting.</title>
2658 We believe this is due to an IPv6-related bug in Mac OS X, but don't fully
2659 understand the issue yet. In any case, changing the proxy setting to
2660 <literal>127.0.0.1</literal> instead of <literal>localhost</literal>
2661 works around the problem.
2665 <!-- ~~~~~ New section ~~~~~ -->
2666 <sect2 renderas="sect3" id="macosxaccountdeletion">
2667 <title>I just upgraded to Mac OS X 10.9 (Mavericks) and now &my-app; has stopped
2670 The upgrade process to Mac OS X Mavericks (10.9) from an earlier version of OS
2671 X deletes all user accounts that are either not part of OS X itself or are
2672 not interactive user accounts (ones you log in with). Since, for the sake of
2673 security, &my-app; runs as a non-privileged user that is created by its
2674 installer (_privoxy), it can no longer start up once that account gets deleted.
2675 The solution is to perform a complete uninstall using the supplied
2676 <application>uninstall.command</application> script (either back up your
2677 configuration files or select to not have the uninstaller remove them when it
2678 prompts you) and then reinstall &my-app; using the installer package and merge
2679 in your configuration.
2683 <sect2 renderas="sect3" id="nohostname">
2684 <title>My logs show many <quote>Unable to get my own hostname</quote> lines.
2687 <application>Privoxy</application> tries to get the hostname of the system
2688 its running on from the IP address of the system interface it is bound to
2689 (from the <filename>config</filename> file
2690 <emphasis>listen-address</emphasis> setting). If the system cannot supply
2691 this information, <application>Privoxy</application> logs this condition.
2694 Typically, this would be considered a minor system configuration error. It is
2695 not a fatal error to <application>Privoxy</application> however, but may
2696 result in a much slower response from <application>Privoxy</application> on
2697 some platforms due to DNS timeouts.
2700 This can be caused by a problem with the local <filename>hosts</filename>
2701 file. If this file has been changed from the original, try reverting it to
2702 see if that helps. Make sure whatever name(s) are used for the local system,
2703 that they resolve both ways.
2706 You should also be able to work around the problem with the
2707 <ulink url="../user-manual/config.html#HOSTNAME">hostname option</ulink>.
2711 <sect2 renderas="sect3" id="inuse">
2712 <title>When I try to launch Privoxy, I get an
2713 error message <quote>port 8118 is already in use</quote> (or similar wording).
2716 Port 8118 is <application>Privoxy's</application> default TCP
2717 <quote>listening</quote> port. Typically this message would mean that there
2718 is already one instance of <application>Privoxy</application> running, and
2719 your system is actually trying to start a second
2720 <application>Privoxy</application> on the same port, which will not work.
2721 (You can have multiple instances but they must be assigned different ports.)
2722 How and why this might happen varies from platform to platform, but you need
2723 to check your installation and start-up procedures.
2727 <sect2 renderas="sect3" id="demoronizer">
2729 Pages with UTF-8 fonts are garbled.
2732 This may be the result of an overly aggressive filter. The filters that
2733 are enabled in the default configuration aren't expected to cause problems
2734 like this. If you enabled the <quote>demoronizer</quote> filter, please
2735 try temporarily disabling it.
2738 If that doesn't help, temporarily disable all filters to see if another
2739 filter could be the culprit. If the problem disappears, enable the filters
2740 one by one, until the problem reappears and the offending filter is found.
2743 Once the problem-causing filter is known, it can be fixed or disabled.
2746 Upgrading <application>Privoxy</application>, or going to the most recent
2747 <filename>default.action</filename> file available from <ulink
2748 url="https://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>
2749 might be worth a try, too.
2753 <sect2 renderas="sect3" id="demoronizer2">
2755 Why are binary files (such as images) corrupted when Privoxy
2759 This may also be caused by an (<link linkend="DEMORONIZER">overly aggressive
2760 filter</link> in conjunction with a web server that is misreporting the content
2761 type. By default binary files are exempted from
2762 <application>Privoxy's</application> filtering
2763 (unless the web server by mistake says the file is something else).
2767 <sect2 renderas="sect3" id="demoronizer3">
2769 What is the <quote>demoronizer</quote> and why is it there?
2772 The original demoronizer was a Perl script that cleaned up HTML pages which
2773 were created with certain Microsoft products. MS has used proprietary extensions
2774 to standardized font encodings (ISO 8859-1), which has caused problems for pages
2775 that are viewed with non-Microsoft products (and are expecting to see a
2776 standard set of fonts). The demoronizer corrected these errors so the pages
2777 displayed correctly. <application>Privoxy</application> borrowed from this
2778 script, introducing a filter based on the original demoronizer, which in turn could
2779 correct these errors on the fly.
2782 But this is only needed in some situations, and will cause serious problems in some
2786 If you are using Microsoft products, you do not need it. If you need to view
2787 pages with UTF-8 characters (such as Cyrillic or Chinese), then it will
2788 cause corruption of the fonts, and thus <emphasis>should not be on</emphasis>.
2791 On the other hand, if you use non-Microsoft products, and you occasionally
2792 notice weird characters on pages, you might want to try it.
2796 <sect2 renderas="sect3" id="windowopen">
2798 Why do I keep seeing <quote>PrivoxyWindowOpen()</quote> in raw source code?
2801 <application>Privoxy</application> is attempting to disable malicious
2802 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink>
2803 in this case, with the <literal>unsolicited-popups</literal>
2804 filter. <application>Privoxy</application> cannot tell very well
2805 <quote>good</quote> code snippets from <quote>bad</quote> code snippets.
2808 If you see this in HTML source, and the page displays without problems, then
2809 this is good, and likely some pop-up window was disabled. If you see this
2810 where it is causing a problem, such as a downloaded program source code file,
2811 then you should set an exception for this site or page such that the
2812 integrity of the page stays in tact by disabling all filtering.
2816 <sect2 renderas="sect3" id="dnserrors">
2818 I am getting too many DNS errors like <quote>404 No Such Domain</quote>. Why
2819 can't Privoxy do this better?
2822 There are potentially several factors here. First of all, the DNS resolution
2823 is done by the underlying operating system -- not
2824 <application>Privoxy</application> itself. <application>Privoxy</application>
2825 merely initiates the process and hands it off, and then later reports
2826 whatever the outcome was and tries to give a coherent message if there seems
2827 to be a problem. In some cases, this might otherwise be mitigated by the
2828 browser itself which might try some work-arounds and alternate approaches (e.g
2829 adding <quote>www.</quote> to the URL).
2832 In other cases, if <application>Privoxy</application> is being chained
2833 with another proxy, this could complicate the issue, and cause undue
2834 delays and timeouts. In the case of a <quote>socks4a</quote> proxy, the socks
2835 server handles all the DNS. <application>Privoxy</application> would just be
2836 the <quote>messenger</quote> which is reporting whatever problem occurred
2837 downstream, and not the root cause of the error.
2841 In any case, versions newer than 3.0.3 include various improvements to help
2842 <application>Privoxy</application> better handle these cases.
2846 <sect2 renderas="sect3" id="allcpu">
2848 At one site Privoxy just hangs, and starts taking
2849 all CPU. Why is this?
2852 This is probably a manifestation of the <quote>100% cpu</quote> problem that
2853 occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines
2854 are in the raw HTML source of the page, and the browser just ignores them. But the
2855 pattern matching in <application>Privoxy's</application> page filtering
2856 mechanism is trying to match against absurdly long strings and this becomes
2857 very CPU-intensive, taking a long, long time to complete.
2860 Until a better solution comes along, disable filtering on these pages,
2861 particularly the <literal>js-annoyances</literal> and
2862 <literal>unsolicited-popups</literal> filters. If you run into this problem
2863 with a recent &my-app; version, please send a problem report.
2867 <sect2 renderas="sect3" id="slowcrawl">
2868 <title>I just installed Privoxy, and all my
2869 browsing has slowed to a crawl. What gives? </title>
2871 This should not happen, and for the overwhelming number of users world-wide,
2872 it does not happen. I would suspect some inadvertent interaction of software
2873 components such as anti-virus software, spyware protectors, personal
2874 firewalls or similar components. Try disabling (or uninstalling) these one
2875 at a time and see if that helps. Either way, if you are using a
2876 recent &my-app; version, please report the problem.
2880 <sect2 renderas="sect3" id="preventcomp">
2881 <title>Why do my filters work on some sites but not on others? </title>
2883 It's probably due to compression. It is a common practice for web servers to
2884 send their content <quote>compressed</quote> in order to speed things up, and
2885 then let the browser <quote>uncompress</quote> them. When compiled with zlib support
2886 &my-app; can decompress content before filtering, otherwise you may want to enable
2888 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>.
2891 As of &my-app; 3.0.9, zlib support is enabled in the default builds.
2896 <sect2 renderas="sect3" id="ssl-warnings">
2897 <title>On some HTTPS sites my browser warns me about unauthenticated content,
2898 the URL bar doesn't get highlighted and the lock symbol appears to be broken.
2899 What's going on?</title>
2901 Probably the browser is requesting ads through HTTPS and &my-app;
2902 is blocking the requests. Privoxy's error messages are delivered
2903 unencrypted and while it's obvious for the browser that the HTTPS
2904 request is already blocked by the proxy, some warn about unauthenticated
2908 To work around the problem you can redirect those requests to an invalid
2909 local address instead of blocking them. While the redirects aren't
2910 encrypted either, many browsers don't care. They simply follow the
2911 redirect, fail to reach a server and display an error message instead
2915 To do that, enable logging to figure out which requests get blocked by
2916 &my-app; and add the hosts (no path patterns) to a section like this:
2921 {+redirect{http://127.0.0.1:0/} -block -limit-connect}
2927 Additionally you have to configure your browser to contact
2928 <quote>127.0.0.1:0</quote> directly (instead of through &my-app;).
2931 To add a proxy exception in <application>Mozilla Firefox</application>
2932 open the <quote>Preferences</quote>, click the <quote>Settings</quote>
2933 button located on the <quote>Network</quote> tab in the <quote>Advanced</quote>
2934 section, and add <quote>127.0.0.1:0</quote> in the <quote>No Proxy for:</quote>
2940 <sect2 renderas="sect3" id="se-linux">
2941 <title>I get selinux error messages. How can I fix this?</title>
2943 Please report the problem to the creator of your selinux policies.
2946 The problem is that some selinux policy writers aren't familiar
2947 with the application they are trying to <quote>secure</quote> and
2948 thus create policies that make no sense.
2951 In <application>Privoxy's</application> case the problem usually
2952 is that the policy only allows outgoing connections for certain
2953 destination ports (e.g. 80 and 443). While this may cover the
2954 standard ports, websites occasionally use other ports as well.
2955 This isn't a security problem and therefore <application>Privoxy's</application>
2956 default configuration doesn't block these requests.
2959 If you really want to block these ports (and don't be able
2960 to load websites that don't use standard ports), you should
2961 configure Privoxy to block these ports as well, so it doesn't
2962 trigger the selinux warnings.
2967 <sect2 renderas="sect3" id="gentoo-ricers">
2968 <title>I compiled &my-app; with Gentoo's portage and it appears to be very slow. Why?</title>
2970 Probably you unintentionally compiled &my-app; without threading support
2971 in which case requests have to be serialized and only one can be served
2975 Check your <quote>USE</quote> flags and make sure they include
2976 <quote>threads</quote>. If they don't, add the flag and rebuild &my-app;.
2979 If you compiled &my-app; with threading support (on POSIX-based systems),
2980 the <quote>Conditional #defines</quote> section on <ulink
2981 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2982 will list <quote>FEATURE_PTHREAD</quote> as <quote>enabled</quote>.
2986 <sect2 renderas="sect3" id="tainted-sockets">
2987 <title>What are tainted sockets and how do I prevent them?</title>
2989 &my-app; marks sockets as tainted when it can't use them to
2990 serve additional requests.
2991 This does not necessarily mean that something went wrong and
2992 information about tainted sockets is only logged if connection
2993 debugging is enabled (debug 2).
2996 For example server sockets that were used for CONNECT requests
2997 (which are used to tunnel https:// requests) are considered tainted
2998 once the client closed its connection to &my-app;.
2999 Technically &my-app; could keep the connection to the server open,
3000 but the server would not accept requests that do not belong to the
3001 previous TLS/SSL session (and the client may even have terminated
3005 Server sockets are also marked tainted when a client requests a
3006 resource, but closes the connection before &my-app; has completely
3007 received (and forwarded) the resource to the client.
3008 In this case the server would (probably) accept additional requests,
3009 but &my-app; could not get the response without completely reading
3010 the leftovers from the previous response.
3013 These are just two examples, there are currently a bit more than
3014 25 scenarios in which a socket is considered tainted.
3017 While sockets can also be marked tainted as a result of a technical
3018 problem that may be worth fixing, the problem will be explicitly
3023 <sect2 renderas="sect3" id="pcre-stack-limit">
3024 <title>After adding my custom filters, &my-app; crashes when visitting certain websites</title>
3026 This can happen if your custom filters require more memory than &my-app;
3028 Usually the problem is that the operating system enforces a stack size limit
3029 that isn't sufficient.
3032 Unless the problem occurs with the filters available in the default configuration,
3033 this is not considered a Privoxy bug.
3036 To prevent the crashes you can rewrite your filter to use less ressources,
3037 increase the relevant memory limit or recompile pcre to use less stack space.
3038 For details please see the
3039 <ulink url="http://pcre.org/original/doc/html/pcrestack.html">pcrestack man page</ulink>
3040 and the documentation of your operating system.
3044 <sect2 renderas="sect3" id="file-permissions">
3045 <title>What to do if editing the config file of privoxy is access denied?</title>
3047 Your userid probably isn't allowed to edit the file.
3048 <!-- show how to check permissions? -->
3049 On Windows you can use the windows equivalent of sudo:
3050 <screen>runas /user:administrator "notepad \privoxy\config.txt"</screen>
3054 or fix the file permissions:
3055 <screen>C:\Privoxy>icacls config.txt
3056 config.txt BUILTIN\Administrators:(I)(F)
3057 NT AUTHORITY\SYSTEM:(I)(F)
3058 BUILTIN\Users:(I)(RX)
3059 NT AUTHORITY\Authenticated Users:(I)(M)
3061 Successfully processed 1 files; Failed processing 0 files
3063 C:\Privoxy>icacls config.txt /grant Lee:F
3064 processed file: config.txt
3065 Successfully processed 1 files; Failed processing 0 files
3067 C:\Privoxy>icacls config.txt
3068 config.txt I3668\Lee:(F)
3069 BUILTIN\Administrators:(I)(F)
3070 NT AUTHORITY\SYSTEM:(I)(F)
3071 BUILTIN\Users:(I)(RX)
3072 NT AUTHORITY\Authenticated Users:(I)(M)
3074 Successfully processed 1 files; Failed processing 0 files
3076 C:\Privoxy></screen>
3080 or try to point-n-click your way through adjusting the file
3081 permissions in windows explorer.
3087 <!-- ~~~~~ New section ~~~~~ -->
3088 <sect1 id="contact"><title>Contacting the developers, Bug Reporting and Feature Requests</title>
3089 <!-- Include contacting.sgml -->
3091 <!-- end contacting -->
3094 <!-- ~~~~~ New section ~~~~~ -->
3095 <sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
3097 <!-- Include copyright.sgml -->
3103 Portions of this document are <quote>borrowed</quote> from the original
3104 <application>Junkbuster</application> (tm) FAQ, and modified as
3105 appropriate for <application>Privoxy</application>.
3108 <!-- ~~~~~ New section ~~~~~ -->
3109 <sect2><title>License</title>
3110 <!-- Include copyright.sgml: -->
3112 <!-- end copyright -->
3114 <!-- ~ End section ~ -->
3116 <!-- ~~~~~ New section ~~~~~ -->
3117 <sect2><title>History</title>
3118 <!-- Include history.sgml -->
3124 <!-- ~ End section ~ -->
3127 <!-- ~~~~~ New section ~~~~~ -->
3129 <sect1 id="seealso"><title>See also</title>
3131 <!-- Include seealso.sgml -->
3141 This program is free software; you can redistribute it
3142 and/or modify it under the terms of the GNU General
3143 Public License as published by the Free Software
3144 Foundation; either version 2 of the License, or (at
3145 your option) any later version.
3147 This program is distributed in the hope that it will
3148 be useful, but WITHOUT ANY WARRANTY; without even the
3149 implied warranty of MERCHANTABILITY or FITNESS FOR A
3150 PARTICULAR PURPOSE. See the GNU General Public
3151 License for more details.
3153 The GNU General Public License should be included with
3154 this file. If not, you can view it at
3155 http://www.gnu.org/copyleft/gpl.html
3156 or write to the Free Software Foundation, Inc.,
3157 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
projects / privoxy.git / blob