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 "3.0.26">
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 $Id: faq.sgml,v 2.128 2016/07/26 10:46:29 fabiankeil Exp $
32 Copyright (C) 2001-2014 Privoxy Developers https://www.privoxy.org/
35 Based partially on the Internet Junkbuster FAQ originally written by and
36 Copyright (C) 1997 Anonymous Coders and Junkbusters Corporation.
37 http://www.junkbusters.com/
39 <Qandaset defaultlabel='qanda'>
54 ========================================================================
55 NOTE: Please read developer-manual/documentation.html before touching
58 Please we keep the info in this file as version independent as possible
59 so we only have to maintain one FAQ. Where significant changes are
60 made to Privoxy configuration, please note the change in such a way that
61 it makes sense to both users of older and newer versions.
62 ========================================================================
68 <article id="index" class="faq">
70 <title>Privoxy Frequently Asked Questions</title>
74 <!-- Completely the wrong markup, but very little is allowed -->
75 <!-- in this part of an article. FIXME -->
76 <link linkend="copyright">Copyright</link> &my-copy; 2001-2016 by
77 <ulink url="https://www.privoxy.org/">Privoxy Developers</ulink>
81 <pubdate>$Id: faq.sgml,v 2.128 2016/07/26 10:46:29 fabiankeil Exp $</pubdate>
85 Note: this should generate a separate page, and a live link to it.
86 But it doesn't for some mysterious reason. Please leave commented
87 unless it can be fixed proper. For the time being, the copyright
88 statement will be in copyright.smgl.
92 <legalnotice id="legalnotice">
94 text goes here ........
104 <orgname>By: Privoxy Developers</orgname>
113 This is here to keep vim syntax file from breaking :/
114 If I knew enough to fix it, I would.
115 PLEASE DO NOT REMOVE! HB: hal@foobox.net
120 This FAQ gives quick answers to frequently asked questions about
121 <ulink url="https://www.privoxy.org/">Privoxy</ulink>.
122 It is not a substitute for the
123 <ulink url="../user-manual/index.html"><citetitle>Privoxy User Manual</citetitle></ulink>.
125 This works, at least in some situtations:
126 Test: <ulink url="privoxy-user-manual.pdf"><citetitle>User Manual</citetitle></ulink>.
130 <!-- Include privoxy.sgml boilerplate: -->
131 <para>What is Privoxy?</para> &p-intro;
132 <!-- end boilerplate -->
135 Please note that this document is a work in progress. This copy represents
136 the state at the release of version &p-version;.
137 You can find the latest version of the document at <ulink
138 url="https://www.privoxy.org/faq/">https://www.privoxy.org/faq/</ulink>.
139 Please see the <link linkend="contact">Contact section</link> if you want to
140 contact the developers.
147 <!-- ~~~~~ New section ~~~~~ -->
149 <sect1 id="general"><title>General Information</title>
150 <sect2 renderas="sect3" id="who-uses"><title>Who should give &my-app; a try?</title>
152 Anyone who is interested in security, privacy, or in
153 finer-grained control over their web and Internet experience.
157 <sect2 renderas="sect3" id="bestchoice"><title>Is Privoxy the best choice for
160 &my-app; is certainly a good choice, especially for those who want more
161 control and security. Those with the willingness to read the documentation
162 and the ability to fine-tune their installation will benefit the most.
165 One of <application>Privoxy's</application>
166 strengths is that it is highly configurable giving you the ability to
167 completely personalize your installation. Being familiar with, or at least
168 having an interest in learning about <ulink
169 url="http://en.wikipedia.org/wiki/Http">HTTP</ulink> and other networking
170 protocols, <ulink url="http://en.wikipedia.org/wiki/Html">HTML</ulink>, and
171 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
172 Expressions</quote></ulink>
173 will be a big plus and will help you get the most out of &my-app;.
174 A new installation just includes a very basic configuration. The user
175 should take this as a starting point only, and enhance it as he or she
176 sees fit. In fact, the user is encouraged, and expected to, fine-tune the
180 Much of <application>Privoxy's</application> configuration can be done
181 with a <ulink url="http://en.wikipedia.org/wiki/Web_browser">Web browser</ulink>.
182 But there are areas where configuration is done using a
183 <ulink url="http://en.wikipedia.org/wiki/Text_editors">text editor</ulink>
184 to edit configuration files. Also note that the web-based action editor
185 doesn't use authentication and should only be enabled in environments
186 where all clients with access to &my-app; listening port can be trusted.
190 <sect2 renderas="sect3" id="proxymoron"><title>What is a <quote>proxy</quote>? How does
191 Privoxy work? </title>
193 A <ulink url="http://en.wikipedia.org/wiki/Proxy_server">web proxy</ulink>
194 is a service, based on a software such as &my-app;, that clients
195 (i.e. browsers) can use instead of connecting to web servers directly.
196 The clients then ask the proxy to request objects (web pages, images, movies etc)
197 on their behalf and to forward the data to the clients.
198 It is a <quote>go-between</quote>. For details, see
199 <ulink url="http://en.wikipedia.org/wiki/Proxy_server">Wikipedia's proxy definition</ulink>.
202 There are many reasons to use web proxies, such as security (firewalling),
203 efficiency (caching) and others, and there are any number of proxies
204 to accommodate those needs.
207 &my-app; is a proxy that is primarily focused on
208 privacy enhancement, ad and junk elimination and freeing the user from
209 restrictions placed on his activities. Sitting between your browser(s) and the Internet,
210 it is in a perfect position to filter outbound personal information that your
211 browser is leaking, as well as inbound junk. It uses a variety of techniques to do
212 this, all of which are under your complete control via the various configuration
213 files and options. Being a proxy also makes it easier to share
214 configurations among multiple browsers and/or users.
218 <sect2 renderas="sect3" id="otherstuff">
219 <title>Does Privoxy do anything more than ad blocking?</title>
221 Yes, ad blocking is but one possible use. There are many, many ways &my-app;
222 can be used to sanitize and customize web browsing.
226 <sect2 renderas="sect3" id="newjb"><title>What is this new version of
227 <quote><citetitle>Junkbuster</citetitle></quote>?</title>
229 <!-- Include history.sgml -->
236 <sect2 renderas="sect3" id="whyprivoxy">
237 <title>Why <quote>Privoxy</quote>? Why change the name from
238 Junkbuster at all?</title>
240 Though outdated, Junkbusters Corporation continued to offer their original
241 version of the <application>Internet Junkbuster</application> for a while,
242 so publishing our <application> Junkbuster</application>-derived software
243 under the same name would have led to confusion.
246 There were also potential legal reasons not to use the
247 <application>Junkbuster</application> name, as it was (and maybe still is)
248 a registered trademark of Junkbusters Corporation.
249 There were, however, no objections from Junkbusters Corporation to the
250 <application>Privoxy</application> project itself, and they, in fact,
251 shared our ideals and goals.
254 The Privoxy developers also believed that there were so many improvements
255 over the original code, that it was time to make a clean break from the past
256 and make a name in their own right.
259 <application>Privoxy</application> is the
260 <quote><emphasis>Privacy Enhancing Proxy</emphasis></quote>. Also, its content
261 modification and junk suppression gives <emphasis>you</emphasis>, the user, more
262 control, more freedom, and allows you to browse your personal and
263 <quote><emphasis>private</emphasis> edition</quote> of the web.
267 <sect2 renderas="sect3" id="differs"><title>How does Privoxy differ
268 from the old Junkbuster?</title>
270 <application>Privoxy</application> picks up where
271 <application>Junkbuster</application> left off.
272 <application>Privoxy</application> still blocks ads and banners,
274 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>, and still
275 helps protect your privacy. But, most of these features have been enhanced,
276 and many new ones have been added, all in the same vein.
279 <application>Privoxy</application>'s new features include:
282 <!-- Include newfeatures.sgml: -->
288 <sect2 renderas="sect3" id="whatsanad">
289 <title>How does Privoxy know what is an ad, and what is not?</title>
291 <application>Privoxy</application>'s approach to blocking ads is twofold:
294 First, there are certain patterns in the <emphasis>locations</emphasis> (URLs)
295 of banner images. This applies to both the path (you wouldn't guess how many
296 web sites serve their banners from a directory called <quote>banners</quote>!)
297 and the host (blocking the big banner hosting services like doublecklick.net
298 already helps a lot). <application>Privoxy</application> takes advantage of this
299 fact by using <ulink url="../user-manual/actions-file.html#AF-PATTERNS">URL
300 patterns</ulink> to sort out and block the requests for things that sound
301 like they would be ads or banners.
304 Second, banners tend to come in certain <emphasis>sizes</emphasis>. But you
305 can't tell the size of an image by its URL without downloading it, and if you
306 do, it's too late to save bandwidth. Therefore, <application>Privoxy</application>
307 also inspects the HTML sources of web pages while they are loaded, and replaces
308 references to images with standard banner sizes by dummy references, so that
309 your browser doesn't request them anymore in the first place.
312 Both of this involves a certain amount of guesswork and is, of course, freely
313 and readily configurable.
317 <sect2 renderas="sect3" id="mistakes">
318 <title>Can Privoxy make mistakes?
319 This does not sound very scientific.</title>
321 Actually, it's a black art ;-) And yes, it is always possible to have a broad
322 rule accidentally block or change something by mistake. You will almost surely
323 run into such situations at some point. It is tricky writing rules to
324 cover every conceivable possibility, and not occasionally get false positives.
328 But this should not be a big concern since the
329 <application>Privoxy</application> configuration is very flexible, and
330 includes tools to help identify these types of situations so they can be
331 addressed as needed, allowing you to customize your installation.
332 (<link linkend="badsite">See the Troubleshooting section below</link>.)
337 <sect2 renderas="sect3" id="configornot">
338 <title>Will I have to configure Privoxy
339 before I can use it?</title>
341 That depends on your expectations.
342 The default installation should give you a good starting
343 point, and block <emphasis>most</emphasis> ads and unwanted content,
344 but many of the more advanced features are off by default, and require
345 you to activate them.
348 You do have to set up your browser to use
349 <application>Privoxy</application> (see the <link
350 linkend="firststep">Installation section below</link>).
353 And you will certainly run into situations where there are false positives,
354 or ads not being blocked that you may not want to see. In these cases, you
355 would certainly benefit by customizing <application>Privoxy's</application>
356 configuration to more closely match your individual situation. And we
357 encourage you to do this. This is where the real power of
358 <application>Privoxy</application> lies!
363 <sect2 renderas="sect3" id="lan">
364 <title>Can Privoxy run as a server on a network?</title>
366 Yes, &my-app; runs as a server already, and can easily be configured to
367 <quote>serve</quote> more than one client. See <link linkend="lanconfig">
368 How can I set up Privoxy to act as a proxy for my LAN</link> below.
372 <sect2 renderas="sect3" id="browsers2"><title>My browser does the same things as
373 Privoxy. Why should I use Privoxy at all?</title>
375 Modern browsers do indeed have <emphasis>some</emphasis> of the same
376 functionality as <application>Privoxy</application>. Maybe this is
377 adequate for you. But <application>Privoxy</application> is very
378 versatile and powerful, and can probably do a number of things
379 your browser just can't.
382 In addition, a proxy is good choice if you use multiple browsers, or
383 have a LAN with multiple computers since &my-app; can run as a server
384 application. This way all the configuration is in one place, and you don't
385 have to maintain a similar configuration for possibly many browsers or
389 Note, however, that it's recommended to leverage both your browser's
390 and <application>Privoxy's</application> privacy enhancing features
391 at the same time. While your browser probably lacks some features
392 &my-app; offers, it should also be able to do some things more
393 reliably, for example restricting and suppressing JavaScript.
397 <sect2 renderas="sect3" id="whytrust"><title>Why should I trust Privoxy?</title>
399 The most important reason is because you have access to
400 <emphasis>everything</emphasis>, and you can control everything. You can
401 check every line of every configuration file yourself. You can check every
402 last bit of source code should you desire. And even if you can't read code,
403 there should be some comfort in knowing that <!-- thousands of -->other people can,
404 and do read it. You can build the software from scratch, if you want,
405 so that you know the executable is clean, and that it is
406 <emphasis>yours</emphasis>. In fact, we encourage this level of scrutiny. It
407 is one reason we use &my-app; ourselves.
411 <sect2 renderas="sect3" id="license"><title>Is there is a license or fee? What about a
412 warranty? Registration?</title>
414 <application>Privoxy</application> is free software and licensed under the <ulink
415 url="http://www.gnu.org/licenses/old-licenses/gpl-2.0.html">GNU General Public License (GPL) version 2</ulink>.
416 It is free to use, copy, modify or distribute as you wish under the terms of this
417 license. Please see the <link linkend="copyright">Copyright</link> section for more
418 information on the license and copyright. Or the <filename>LICENSE</filename> file
419 that should be included.
422 There is <emphasis>no warranty</emphasis> of any kind, expressed, implied or otherwise.
423 That is something that would cost real money ;-) There is no registration either.
428 <sect2 renderas="sect3" id="spyware">
429 <title>Can Privoxy remove spyware? Adware? Viruses?</title>
431 No, at least not reliably enough to trust it. &my-app; is not designed to be
432 a malware removal tool and the default configuration doesn't even try to
433 filter out any malware.
436 &my-app; could help prevent contact from (known) sites that use such
437 tactics with appropriate configuration rules, and thus could conceivably
438 prevent contamination from such sites. However, keeping such a configuration
439 up to date would require a lot of time and effort that would be better spend
440 on keeping your software itself up to date so it doesn't have known
446 <sect2 renderas="sect3" id="otherads">
447 <title>Can I use Privoxy with other ad-blocking software?</title>
449 &my-app; should work fine with other proxies and other software in general.
452 But it is probably not necessary to use &my-app; in conjunction with other
453 ad-blocking products, and this could conceivably cause undesirable results.
454 It might be better to choose one software or the other and work a little to
455 tweak its configuration to your liking.
458 Note that this is an advice specific to ad blocking.
462 <sect2 renderas="sect3" id="help-the-developers"><title>I would like to help you, what can I do?</title>
464 <sect3 renderas="sect4" id="participate"><title>Would you like to participate?</title>
466 Well, we <emphasis>always</emphasis> need help. There is something for
467 everybody who wants to help us. We welcome new developers, packagers,
468 testers, documentation writers or really anyone with a desire to help in
469 any way. You <emphasis>DO NOT</emphasis> need to be a
470 <quote>programmer</quote>. There are many other tasks available. In fact,
471 the programmers often can't spend as much time programming because of some
472 of the other, more mundane things that need to be done, like checking the
473 Tracker feedback sections or responding to user questions on the mailing
477 So first thing, subscribe to the <ulink
478 url="https://lists.privoxy.org/mailman/listinfo/privoxy-users">Privoxy Users</ulink>
479 or the <ulink url="https://lists.privoxy.org/mailman/listinfo/privoxy-devel">Privoxy
480 Developers</ulink> mailing list, join the discussion, help out other users, provide general
481 feedback or report problems you noticed.
484 If you intend to help out with the trackers, you also might want to <ulink
485 url="https://sourceforge.net/user/registration">get an account on SourceForge.net</ulink>
486 so we don't confuse you with the other name-less users.
489 We also have a <ulink
490 url="../developer-manual/index.html">Developer's Manual</ulink>.
491 While it is partly out of date, it's still worth reading.
494 Our <ulink url="http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup">TODO list</ulink>
495 may be of interest to you as well.
496 Please let us know if you want to work on one of the items listed.
500 <sect3 renderas="sect4" id="donate"><title>Would you like to donate?</title>
502 Donations are welcome. Our
503 <ulink url="http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup">TODO list</ulink>
504 is rather long and being able to pay one (or more) developers to work on Privoxy
505 would make a huge difference, even if it was only for a couple of weeks. Donations may
506 also be used for Privoxy-related travel expenses (for example to attend conferences),
507 for hardware used for Privoxy development and for hosting expenses etc.
511 <application>Privoxy</application> is an associated
512 project of <ulink url="http://www.spi-inc.org/">Software
513 in the Public Interest (SPI)</ulink>, which allows us to receive
514 tax-deductible donations in the United States. If you want to donate through
515 SPI, please use <ulink url="http://www.spi-inc.org/donations">SPI's donation page</ulink>
516 to see what the options are.
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.
592 The details may change over time but changes will only affect new sponsors
593 (or existing sponsors that explicitly agreed to the changes).
596 If you want to become a sponsor, please contact
597 <ulink url="mailto:fk@fabiankeil.de">Fabian Keil</ulink>.
598 New sponsors are only accepted if no developer objects.
606 <!-- ~~~~~ New section ~~~~~ -->
608 <sect1 id="installation"><title>Installation</title>
610 <sect2 renderas="sect3" id="whichbrowsers">
611 <title>Which browsers are supported by Privoxy?</title>
613 Any browser that can be configured to use a proxy, which
614 should be virtually all browsers, including
615 <application>Firefox</application>, <application>Internet
616 Explorer</application>, <application>Opera</application>, and
617 <application>Safari</application> among others.
618 Direct browser support is not an absolute requirement since
619 <application>Privoxy</application> runs as a separate application and talks
620 to the browser in the standardized HTTP protocol, just like a web server
625 <sect2 renderas="sect3" id="whichos">
626 <title>Which operating systems are supported?</title>
628 Include supported.sgml here:
633 <sect2 renderas="sect3" id="email-client">
634 <title>Can I use Privoxy with my email client?</title>
636 As long as there is some way to set a HTTP proxy for the client, then yes,
637 any application can be used, whether it is strictly speaking a
638 <quote>browser</quote> or not. Though this may not be the best approach for
639 dealing with some of the common abuses of HTML in email. See <link
640 linkend="outlook">How can I configure <application>Privoxy</application>
641 with <application>Outlook</application>?</link> below for more on
645 Be aware that HTML email presents a number of unique security and privacy
646 related issues, that can require advanced skills to overcome. The developers
647 recommend using email clients that can be configured to convert HTML to plain
648 text for these reasons.
652 <!-- Nobody is going to still be doing this!
653 <sect2 renderas="sect3" id="newinstall"><title>Can I install
654 Privoxy over Junkbuster?</title>
656 We recommend you un-install <application>Junkbuster</application>
657 first to minimize conflicts and confusion. You may want to
658 save your old configuration files for future reference. The configuration
659 files and syntax have substantially changed, so you will need to manually
660 port your old patterns. See the <ulink url="../user-manual/upgradersnote.html">note
661 to upgraders</ulink> and <ulink url="../user-manual/installation.html">installation
662 chapter</ulink> in the <ulink url="../user-manual/index.html">User Manual</ulink>
666 Note: Some installers may automatically un-install
667 <application>Junkbuster</application>, if present!
673 <sect2 renderas="sect3" id="firststep">
674 <title>I just installed Privoxy. Is there anything
675 special I have to do now?</title>
678 All browsers should be told to use <application>Privoxy</application>
679 as a proxy by specifying the correct proxy address and port number
680 in the appropriate configuration area for the browser. It's possible
681 to combine &my-app; with a packet filter to intercept HTTP requests
682 even if the client isn't explicitly configured to use &my-app;,
683 but where possible, configuring the client is recommended. See
684 <ulink url="../user-manual/startup.html">the User Manual for more
685 details</ulink>. You should also flush your browser's memory and disk
686 cache to get rid of any cached junk items, and remove any stored
687 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>.
693 <sect2 renderas="sect3" id="localhost"><title>What is the proxy address of Privoxy?</title>
695 If you set up the <application>Privoxy</application> to run on
696 the computer you browse from (rather than your ISP's server or some
697 networked computer on a LAN), the proxy will be on <literal>127.0.0.1</literal>
698 (sometimes referred to as <quote>localhost</quote>,
699 which is the special name used by every computer on the Internet to refer
700 to itself) and the port will be 8118 (unless you used the <ulink
701 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
702 config option to tell <application>Privoxy</application> to run on
706 When configuring your browser's proxy settings you typically enter
707 the word <quote>localhost</quote> or the IP address <quote>127.0.0.1</quote>
708 in the boxes next to <quote>HTTP</quote> and <quote>Secure</quote> (HTTPS) and
709 then the number <quote>8118</quote> for <quote>port</quote>.
710 This tells your browser to send all web requests to <application>Privoxy</application>
711 instead of directly to the Internet.
714 <application>Privoxy</application> can also be used to proxy for
715 a Local Area Network. In this case, your would enter either the IP
716 address of the LAN host where <application>Privoxy</application>
717 is running, or the equivalent hostname, e.g. <literal>192.168.1.1</literal>.
718 Port assignment would be same as above. Note that
719 <application>Privoxy</application> doesn't listen on any LAN interfaces by
723 <application>Privoxy</application> does not currently handle
724 any other protocols such as FTP, SMTP, IM, IRC, ICQ, etc.
728 <sect2 renderas="sect3" id="nothing">
729 <title>I just installed Privoxy, and nothing is happening.
730 All the ads are there. What's wrong?</title>
733 Did you configure your browser to use <application>Privoxy</application>
734 as a proxy? It does not sound like it. See above. You might also try flushing
735 the browser's caches to force a full re-reading of pages. You can verify
736 that <application>Privoxy</application> is running, and your browser
737 is correctly configured by entering the special URL:
738 <ulink url="http://p.p/">http://p.p/</ulink>.
739 <!-- Use http://p.p/ instead of http://config.privoxy.org/ here because
740 of potential redirect caching problem (see next Q). -->
741 This should take you to a page titled <quote>This is Privoxy..</quote> with
742 access to <application>Privoxy's</application> internal configuration.
743 If you see this, then you are good to go. If you receive a page saying
744 <quote>Privoxy is not running</quote>, then the browser is not set up to use
745 your <application>Privoxy</application> installation.
746 If you receive anything else (probably nothing at all), it could either
747 be that the browser is not set up correctly, or that
748 <application>Privoxy</application> is not running at all. Check the <ulink
749 url="../user-manual/config.html#LOGFILE">log file</ulink>. For instructions
750 on starting <application>Privoxy</application> and browser configuration,
751 see the <ulink url="https://www.privoxy.org/user-manual/startup.html">chapter
752 on starting <application>Privoxy</application></ulink> in the
753 <ulink url="https://www.privoxy.org/user-manual/">User Manual</ulink>.
758 <sect2 renderas="sect3" id="notused">
759 <title>I get a <quote>Privoxy is not being used</quote> dummy page although
760 Privoxy is running and being used.</title>
763 First, make sure that Privoxy is <emphasis>really</emphasis> running and
764 being used by visiting <ulink url="http://p.p/">http://p.p/</ulink>. You
765 should see the <application>Privoxy</application> main page. If not, see
766 the <ulink url="https://www.privoxy.org/user-manual/startup.html">chapter
767 on starting <application>Privoxy</application></ulink> in the
768 <ulink url="https://www.privoxy.org/user-manual/">User Manual</ulink>.
772 Now if <ulink url="http://p.p/">http://p.p/</ulink> works for you, but
773 other parts of <application>Privoxy</application>'s web interface show
774 the dummy page, your browser has cached a redirection it encountered before
775 <application>Privoxy</application> was being used. You need to clear your
776 browser's cache. Note that shift-reloading the dummy page won't help, since
777 that'll only refresh the dummy page, not the redirection that lead you there.
781 The procedure for clearing the cache varies from browser to browser. For
782 example, <application>Mozilla/Netscape</application> users would click
783 <guibutton>Edit</guibutton> --> <guibutton>Preferences</guibutton> -->
784 <guibutton>Advanced</guibutton> --> <guibutton>Cache</guibutton> and
785 then click both <quote><guibutton>Clear Memory Cache</guibutton></quote>
786 and <quote><guibutton>Clear Disk Cache</guibutton></quote>.
787 In some <application>Firefox</application> versions it's
788 <guibutton>Tools</guibutton> --> <guibutton>Options</guibutton> -->
789 <guibutton>Privacy</guibutton> --> <guibutton>Cache</guibutton> and
790 then click <quote><guibutton>Clear Cache Now</guibutton></quote>.
791 <!-- In my Firefox versions it's the Netscape way. fk 2007-11-19-->
798 <!-- ~~~~~ New section ~~~~~ -->
800 <sect1 id="configuration"><title>Configuration</title>
801 <sect2 renderas="sect3" id="actionsfile">
802 <title>What exactly is an <quote>actions</quote> file?</title>
805 &my-app; utilizes the concept of <quote>
806 <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink></quote>
807 that are used to manipulate and control web page data.
808 <ulink url="../user-manual/actions-file.html">Actions files</ulink>
809 are where these <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink>
810 that <application>Privoxy</application> could take while processing a certain
811 request, are configured. Typically, you would define a set of default actions
812 that apply globally to all URLs, then add exceptions to these defaults where needed.
813 There is a wide array of actions available that give the user a high degree
814 of control and flexibility on how to process each and every web page.
818 Actions can be defined on a <ulink
819 url="../user-manual/actions-file.html#AF-PATTERNS">URL pattern</ulink> basis, i.e.
820 for single URLs, whole web sites, groups or parts thereof etc. Actions can also be
821 grouped together and then applied to requests matching one or more patterns.
822 There are many possible actions that might apply to any given site. As an example,
823 if you are blocking <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
824 as one of your default actions, but need to accept cookies from a given site,
825 you would need to define an exception for this site in one of your actions
826 files, preferably in <filename>user.action</filename>.
831 <sect2 renderas="sect3" id="actionss">
832 <title>The <quote>actions</quote> concept confuses me. Please list
833 some of these <quote>actions</quote>.</title>
835 For a comprehensive discussion of the actions concept, please refer
836 to the <ulink url="../user-manual/actions-file.html">actions file
837 chapter</ulink> in the <ulink url="../user-manual/index.html">User
838 Manual</ulink>. It includes a <ulink
839 url="../user-manual/actions-file.html#ACTIONS">list of all actions</ulink>
840 and an <ulink url="../user-manual/actions-file.html#ACT-EXAMPLES">actions
841 file tutorial</ulink> to get you started.
846 <sect2 renderas="sect3" id="actconfig">
847 <title>How are actions files configured? What is the easiest
848 way to do this?</title>
851 Actions files are just text files in a special syntax and can be edited
852 with a text editor. But probably the easiest way is to access
853 <application>Privoxy</application>'s user interface with your web browser
854 at <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
855 (Shortcut: <ulink url="http://p.p/">http://p.p/</ulink>) and then select
856 <quote><ulink url="http://config.privoxy.org/show-status">View &
857 change the current configuration</ulink></quote> from the menu. Note
858 that this feature must be explicitly enabled in the main config file
860 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
865 <sect2 renderas="sect3">
866 <title>There are several different <quote>actions</quote> files. What are
867 the differences?</title>
869 Please have a look at the <ulink url="../user-manual/actions-file.html">the actions chapter</ulink>
870 in the <ulink url="../user-manual/index.html">User Manual</ulink> for a detailed explanation.
875 <sect2 renderas="sect3" id="getupdates"><title>Where can I get updated Actions Files?</title>
877 Based on your feedback and the continuing development, updates of
878 <filename>default.action</filename> will be
879 made available from time to time on the <ulink
880 url="https://sourceforge.net/project/showfiles.php?group_id=11118">files section</ulink> of
881 our <ulink url="https://sourceforge.net/projects/ijbswa/">project page</ulink>.
885 If you wish to receive an email notification whenever we release updates of
886 <application>Privoxy</application> or the actions file, <ulink
887 url="https://lists.privoxy.org/mailman/listinfo/privoxy-announce">subscribe
888 to our announce mailing list</ulink>, privoxy-announce@lists.privoxy.org.
893 <sect2 renderas="sect3" id="newconfig"><title>Can I use my old config files?</title>
895 The syntax and purpose of configuration files has remained roughly the
896 same throughout the 3.x series, but backwards compatibility is not guaranteed.
897 Also each release contains updated, <quote>improved</quote> versions and it is
898 therefore strongly recommended to install the newer configuration files
899 and merge back your modifications.
903 <sect2 renderas="sect3" id="difficult">
904 <title>Why is the configuration so complicated?</title>
906 <quote>Complicated</quote> is in the eye of the beholder.
909 Privoxy is currently mainly written by and for people who are already
910 familiar with the underlying concepts like regular expressions, HTTP and HTML,
911 or are willing to become familiar with them to be able to get the most
912 out of a powerful and flexible tool such as Privoxy.
915 While everybody is expected to be able to get a Privoxy default installation
916 up and running, fine-tuning requires a certain amount of background
917 information and Privoxy's documentation mainly concentrates on the
918 Privoxy-specific parts while only providing references to the rest.
921 If you or anyone you know has the skills, time and energy to
922 reduce the barrier of entry, please <link linkend="participate">get involved</link>.
926 <sect2 renderas="sect3" id="yahoo"><title>How can I make my Yahoo/Hotmail/Gmail account work?</title>
928 The default configuration shouldn't impact the usability of any of these services.
929 It may, however, make all <ulink
930 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
931 temporary, so that your browser will forget your
932 login credentials in between browser sessions. If you would like not to have to log
933 in manually each time you access those websites, simply turn off all cookie handling
934 for them in the <filename>user.action</filename> file. An example for yahoo might
938 <screen># Allow all cookies for Yahoo login:
940 { -<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> }
941 .login.yahoo.com</screen>
944 These kinds of sites are often quite complex and heavy with
945 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> and
946 thus <quote>fragile</quote>. So if <emphasis>still</emphasis> a problem,
948 url="../user-manual/actions-file.html#ALIASES">alias</ulink> just for such
952 <screen># Gmail is a _fragile_ site:
954 { <literal>fragile</literal> }
956 mail.google.com</screen>
959 Be sure to flush your browser's caches whenever making these kinds of
960 changes, just to make sure the changes <quote>take</quote>.
963 Make sure the domain, host and path are appropriate as well. Your browser can
964 tell you where you are specifically and you should use that information for
965 your configuration settings. Note that above it is not referenced as
966 <literal>gmail.com</literal>, which is a valid domain name.
971 <sect2 renderas="sect3" id="configfiles"> <title>What's the difference between the
972 <quote>Cautious</quote>, <quote>Medium</quote> and <quote>Advanced</quote> defaults?</title>
974 Configuring <application>Privoxy</application> is not entirely trivial. To
975 help you get started, we provide you with three different default action
976 <quote>profiles</quote> in the web based actions file editor at <ulink
977 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
978 See the <ulink url="../user-manual/actions-file.html"><citetitle>User
979 Manual</citetitle></ulink> for a list of actions, and how the default
984 Where the defaults are likely to break some sites, exceptions for
985 known popular <quote>problem</quote> sites are included, but in
986 general, the more aggressive your default settings are, the more exceptions
987 you will have to make later. New users are best to start off in
988 <quote>Cautious</quote> setting. This is safest and will have the fewest
989 problems. See the <ulink
990 url="../user-manual/index.html"><citetitle>User Manual</citetitle></ulink>
991 for a more detailed discussion.
995 It should be noted that the <quote>Advanced</quote> profile (formerly known
996 as the <quote>Adventuresome</quote> profile) is more
997 aggressive, and will make use of some of
998 <application>Privoxy's</application> advanced features. Use at your own risk!
1003 <sect2 renderas="sect3" id="browseconfig"> <title>Why can I change the configuration
1004 with a browser? Does that not raise security issues?</title>
1006 It may seem strange that regular users can edit the config files with their
1007 browsers, although the whole <filename>/etc/privoxy</filename> hierarchy
1008 belongs to the user <quote>privoxy</quote>, with only 644 permissions.
1011 When you use the browser-based editor, <application>Privoxy</application>
1012 itself is writing to the config files. Because
1013 <application>Privoxy</application> is running as the user <quote>privoxy</quote>,
1014 it can update its own config files.
1017 If you run <application>Privoxy</application> for multiple untrusted users (e.g. in
1018 a LAN) or aren't entirely in control of your own browser, you will probably want
1019 to make sure that the web-based editor and remote toggle features are
1020 <quote>off</quote> by setting <quote><literal><ulink
1021 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>
1022 0</literal></quote> and <quote><literal><ulink
1023 url="../user-manual/config.html#ENABLE-REMOTE-TOGGLE">enable-remote-toggle</ulink>
1024 0</literal></quote> in the <ulink url="../user-manual/config.html">main configuration file</ulink>.
1027 As of &my-app; 3.0.7 these options are disabled by default.
1032 <sect2 renderas="sect3" id="filterfile">
1033 <title>What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>?</title>
1035 The <ulink url="../user-manual/filter-file.html"><filename>default.filter</filename></ulink>
1036 file is where <emphasis>filters</emphasis> as supplied by the developers are defined.
1037 Filters are a special subset of actions that can be used to modify or
1038 remove web page content or headers on the fly. Content filters can
1039 be applied to <emphasis>anything</emphasis> in the page source,
1040 header filters can be applied to either server or client headers.
1041 Regular expressions are used to accomplish this.
1044 There are a number of pre-defined filters to deal with common annoyances. The
1045 filters are only defined here, to invoke them, you need to use the
1047 url="../user-manual/actions-file.html#FILTER"><literal>filter</literal>
1048 action</ulink> in one of the actions files. Content filtering is automatically
1049 disabled for inappropriate MIME types, but if you know better than Privoxy
1050 what should or should not be filtered you can filter any content you like.
1054 <emphasis>not</emphasis> be confused with <ulink
1055 url="../user-manual/actions-file.html#BLOCK"><literal>blocks</literal></ulink>, which
1056 is a completely different action, and is more typically used to block ads and
1061 If you are familiar with regular expressions, and HTML, you can look at
1062 the provided <filename>default.filter</filename> with a text editor and define
1063 your own filters. This is potentially a very powerful feature, but
1064 requires some expertise in both regular expressions and HTML/HTTP.
1065 <![%p-newstuff;[ You should
1066 place any modifications to the default filters, or any new ones you create
1067 in a separate file, such as <filename>user.filter</filename>, so they won't
1068 be overwritten during upgrades.
1069 The ability to define multiple filter files
1070 in <filename>config</filename> is a new feature as of v. 3.0.5.]]>
1074 There is no GUI editor option for this part of the configuration,
1075 but you can disable/enable the various pre-defined filters of the included
1076 <filename>default.filter</filename> file with the <ulink
1077 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1078 Note that the custom actions editor must be explicitly enabled in
1079 the main config file (see <ulink
1080 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
1084 If you intend to develop your own filters, you might want to have a look at
1086 url="https://www.fabiankeil.de/sourcecode/pft/">Privoxy-Filter-Test</ulink>.
1091 <sect2 renderas="sect3" id="lanconfig">
1092 <title>How can I set up Privoxy to act as a proxy for my
1095 By default, <application>Privoxy</application> only responds to requests
1096 from <literal>127.0.0.1</literal> (localhost). To have it act as a server for
1097 a network, this needs to be changed in the <ulink
1098 url="../user-manual/config.html">main configuration file</ulink>. Look for
1100 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink></literal>
1101 option, which may be commented out with a <quote>#</quote> symbol. Make sure
1102 it is uncommented, and assign it the address of the LAN gateway interface,
1103 and port number to use. Assuming your LAN address is 192.168.1.1 and you
1104 wish to run <application>Privoxy</application> on port 8118, this line
1110 listen-address 192.168.1.1:8118</screen>
1114 Save the file, and restart <application>Privoxy</application>. Configure
1115 all browsers on the network then to use this address and port number.
1119 Alternately, you can have <application>Privoxy</application> listen on
1120 all available interfaces:
1125 listen-address :8118</screen>
1129 And then use <application>Privoxy's</application>
1131 url="../user-manual/config.html#PERMIT-ACCESS">permit-access</ulink>
1132 feature to limit connections. A firewall in this situation is recommended
1137 The above steps should be the same for any TCP network, regardless of
1142 If you run <application>Privoxy</application> on a LAN with untrusted users,
1143 we recommend that you double-check the <ulink
1144 url="../user-manual/config.html#ACCESS-CONTROL">access control and security</ulink>
1151 <sect2 renderas="sect3" id="noseeum">
1152 <title>Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
1154 The replacement for blocked images can be controlled with the <ulink
1155 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1156 action</ulink>. You have the choice of a checkerboard pattern, a transparent 1x1 GIF
1157 image (aka <quote>blank</quote>), or a redirect to a custom image of your choice.
1158 Note that this choice only has effect for images which are blocked as images, i.e.
1159 whose URLs match both a <literal><ulink
1160 url="../user-manual/actions-file.html#HANDLE-AS-IMAGE">handle-as-image</ulink></literal>
1161 <emphasis>and</emphasis> <literal><ulink
1162 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> action.
1165 If you want to see nothing, then change the <ulink
1166 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1167 action</ulink> to <quote>blank</quote>. This can be done by editing the
1168 <filename>user.action</filename> file, or through the <ulink
1169 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1174 <sect2 renderas="sect3" id="whyseeum">
1175 <title>Why would anybody want to see a checkerboard pattern?</title>
1177 Remember that <link linkend="whatsanad">telling which image is an ad and which
1178 isn't</link>, is an educated guess. While we hope that the standard configuration
1179 is rather smart, it will make occasional mistakes. The checkerboard image is visually
1180 decent, and it shows you where images have been blocked, which can be very
1181 helpful in case some navigation aid or otherwise innocent image was
1182 erroneously blocked. It is recommended for new users so they can
1183 <quote>see</quote> what is happening. Some people might also enjoy seeing how
1184 many banners they <emphasis>don't</emphasis> have to see.
1189 <sect2 renderas="sect3" id="blockedbytext">
1190 <title>I see some images being replaced with text
1191 instead of the checkerboard image. Why and how do I get rid of this?</title>
1193 This happens when the banners are not embedded in the HTML code of the
1194 page itself, but in separate HTML (sub)documents that are loaded into (i)frames
1195 or (i)layers, and these external HTML documents are blocked. Being non-images
1196 they get replaced by a substitute HTML page rather than a substitute image,
1197 which wouldn't work out technically, since the browser expects and accepts
1198 only HTML when it has requested an HTML document.
1201 The substitute page adapts to the available space and shows itself as a
1202 miniature two-liner if loaded into small frames, or full-blown with a
1203 large red "BLOCKED" banner if space allows.
1206 If you prefer the banners to be blocked by images, you must see to it that
1207 the HTML documents in which they are embedded are not blocked. Clicking
1208 the <quote>See why</quote> link offered in the substitute page will show
1209 you which rule blocked the page. After changing the rule and un-blocking
1210 the HTML documents, the browser will try to load the actual banner images
1211 and the usual image blocking will (hopefully!) kick in.
1216 <sect2 renderas="sect3" id="srvany">
1217 <title>Can Privoxy run as a service
1218 on Win2K/NT/XP?</title>
1221 Yes. Version 3.0.5 introduces full <application>Windows</application> service
1222 functionality. See <ulink url="../user-manual/installation.html#installation-pack-win">
1223 the <citetitle>User Manual</citetitle></ulink> for details on how to install and configure
1224 <application>Privoxy</application> as a service.
1227 Earlier ]]>3.x versions could run as a system service using <command>srvany.exe</command>.
1228 See the discussion at <ulink
1229 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>,
1230 for details, and a sample configuration.
1235 <sect2 renderas="sect3" id="otherproxy">
1236 <title>How can I make Privoxy work with other proxies?</title>
1238 This can be done and is often useful to combine the benefits of
1239 <application>Privoxy</application> with those of a another proxy,
1240 for example to cache content.
1242 url="../user-manual/config.html#FORWARDING">forwarding chapter</ulink>
1243 in the <ulink url="../user-manual/index.html">User Manual</ulink> which
1244 describes how to do this. If you intend to use Privoxy with Tor,
1245 please also have a look at
1246 <link linkend="TOR">How do I use Privoxy together with Tor</link>.
1250 <sect2 renderas="sect3" id="port-80">
1251 <title>Can I just set Privoxy to use port 80
1252 and thus avoid individual browser configuration?</title>
1255 No, its more complicated than that. This only works with special kinds
1256 of proxies known as <quote>intercepting</quote> proxies
1257 (<link linkend="INTERCEPTING">see below</link>).
1262 <sect2 renderas="sect3" id="transparent">
1263 <title>Can Privoxy run as a <quote>transparent
1264 </quote> proxy?</title>
1266 The whole idea of Privoxy is to modify client requests
1267 and server responses in all sorts of ways and therefore
1268 it's not a transparent proxy as described in
1269 <ulink url="http://tools.ietf.org/html/rfc2616">RFC 2616</ulink>.
1272 However, some people say <quote>transparent proxy</quote> when they
1273 mean <quote>intercepting proxy</quote>. If you are one of them,
1274 please read the <link linkend="INTERCEPTING">next entry</link>.
1279 <sect2 renderas="sect3" id="intercepting">
1280 <title>Can Privoxy run as a <quote>intercepting</quote> proxy?</title>
1282 <application>Privoxy</application> can't intercept traffic itself,
1283 but it can handle requests that where intercepted and redirected
1284 with a packet filter (like <application>PF</application> or
1285 <application>iptables</application>), as long as the <literal>Host</literal>
1289 As the <literal>Host</literal> header is required by HTTP/1.1 and as most
1290 web sites rely on it anyway, this limitation shouldn't be a problem.
1293 Please refer to your packet filter's documentation to learn how to
1294 intercept and redirect traffic into <application>Privoxy</application>.
1295 Afterward you just have to configure <application>Privoxy</application> to
1296 <ulink url="../user-manual/config.html#ACCEPT-INTERCEPTED-REQUESTS">accept
1297 intercepted requests</ulink>.
1302 <sect2 renderas="sect3" id="outlook">
1303 <title>How can I configure Privoxy for use with Outlook?</title>
1305 Versions of <application>Outlook</application> prior to Office 2007, use
1306 <application>Internet Explorer</application> components to both render HTML,
1307 and fetch any HTTP requests that may be embedded in an HTML email. So however
1308 you have <application>Privoxy</application> configured to work with IE, this
1309 configuration should automatically be shared, at least with older version of
1313 Starting with Office 2007, Microsoft is instead using the MS-Word rendering
1314 engine with Outlook. It is unknown whether this can be configured to use a
1316 <!-- FIXME HB 2009-02-15 -->
1320 <sect2 renderas="sect3" id="outlook-more">
1321 <title>How can I have separate rules just for HTML mail?</title>
1323 The short answer is, you can't. <application>Privoxy</application> has no way
1324 of knowing which particular application makes a request, so there is no way to
1325 distinguish between web pages and HTML mail.
1326 <application>Privoxy</application> just blindly proxies all requests. In the
1327 case of <application>Outlook Express</application> (see above), OE uses
1328 IE anyway, and there is no way for <application>Privoxy</application> to ever
1329 be able to distinguish between them (nor could any other proxy type application for
1333 For a good discussion of some of the issues involved (including privacy and
1334 security issues), see
1335 <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>.
1339 <sect2 renderas="sect3" id="sneaky-cookies">
1340 <title>I sometimes notice cookies sneaking through. How?</title>
1343 url="http://en.wikipedia.org/wiki/Browser_cookie">Cookies</ulink> can be
1344 set in several ways. The classic method is via the
1345 <literal>Set-Cookie</literal> HTTP header. This is straightforward, and an
1346 easy one to manipulate, such as the &my-app; concept of
1347 <ulink url="../user-manual/actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</ulink>.
1348 There is also the possibility of using
1349 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> to
1350 set cookies (&my-app; calls these <literal>content-cookies</literal>). This
1351 is trickier because the syntax can vary widely, and thus requires a certain
1352 amount of guesswork. It is not realistic to catch all of these short of
1353 disabling Javascript, which would break many sites. And lastly, if the
1354 cookies are embedded in a HTTPS/SSL secure session via Javascript, they are beyond
1355 <application>Privoxy's</application> reach.
1358 All in all, &my-app; can help manage cookies in general, can help minimize
1359 the loss of privacy posed by cookies, but can't realistically stop all
1364 <sect2 renderas="sect3" id="evil-cookies">
1365 <title>Are all cookies bad? Why?</title>
1367 No, in fact there are many beneficial uses of
1369 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>. Cookies are just a
1370 method that browsers can use to store data between pages, or between browser
1371 sessions. Sometimes there is a good reason for this, and the user's life is a
1372 bit easier as a result. But there is a long history of some websites taking
1373 advantage of this layer of trust, and using the data they glean from you and
1374 your browsing habits for their own purposes, and maybe to your potential
1375 detriment. Such sites are using you and storing their data on your system.
1376 That is why the privacy conscious watch from whom those cookies come, and why
1377 they really <emphasis>need</emphasis> to be there.
1381 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">Wikipedia cookie
1382 definition</ulink> for more.
1386 <sect2 renderas="sect3" id="allow-cookies">
1387 <title>How can I allow permanent cookies for my trusted sites?</title>
1390 There are several actions that relate to cookies. The default behavior is to
1391 allow only <quote>session cookies</quote>, which means the cookies only last
1392 for the current browser session. This eliminates most kinds of abuse related
1393 to cookies. But there may be cases where you want cookies to last.
1396 To disable all cookie actions, so that cookies are allowed unrestricted,
1397 both in and out, for <literal>example.com</literal>:
1401 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
1402 .example.com</screen>
1405 Place the above in <filename>user.action</filename>. Note that some of these may
1406 be off by default anyway, so this might be redundant, but there is no harm
1407 being explicit in what you want to happen. <filename>user.action</filename>
1408 includes an alias for this situation, called
1409 <literal>allow-all-cookies</literal>.
1413 <sect2 renderas="sect3" id="multiples">
1414 <title>Can I have separate configurations for different users?</title>
1416 Each instance of <application>Privoxy</application> has its own
1417 configuration, including such attributes as the TCP port that it listens on.
1418 What you can do is run multiple instances of <application>Privoxy</application>, each with
1420 <ulink url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
1421 configuration setting, and configuration path, and then
1422 each of these can have their own configurations. Think of it as per-port
1426 Simple enough for a few users, but for large installations, consider having
1427 groups of users that might share like configurations.
1431 <sect2 renderas="sect3" id="whitelists">
1432 <title>Can I set-up Privoxy as a whitelist of
1433 <quote>good</quote> sites?</title>
1435 Sure. There are a couple of things you can do for simple white-listing.
1436 Here's one real easy one:
1439 ############################################################
1441 ############################################################
1442 { <ulink url="../user-manual/actions-file.html#BLOCK">+block</ulink> }
1443 / # Block *all* URLs
1445 ############################################################
1447 ############################################################
1448 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1451 games.example.com</screen>
1453 This allows access to only those three sites by first blocking all URLs, and
1454 then subsequently allowing three specific exceptions.
1457 Another approach is <application>Privoxy's</application>
1458 <literal>trustfile</literal> concept, which incorporates the notion of
1459 <quote>trusted referrers</quote>. See the <ulink
1460 url="../user-manual/config.html#TRUSTFILE">Trust documentation</ulink>
1464 These are fairly simple approaches and are not completely foolproof. There
1465 are various other configuration options that should be disabled (described
1466 elsewhere here and in <ulink url="../user-manual/">the User Manual</ulink>)
1467 so that users can't modify their own configuration and easily circumvent the
1472 <sect2 renderas="sect3" id="no-adblock">
1473 <title>How can I turn off ad-blocking?</title>
1475 Ad blocking is achieved through a complex application of various &my-app;
1476 <ulink url="../user-manual/actions-file.html">actions</ulink>. These
1477 actions are deployed against simple images, banners, flash animations,
1478 text pages, JavaScript, pop-ups and pop-unders, etc., so its not as simple as
1479 just turning one or two actions off. The various actions that make up
1480 &my-app; ad blocking are hard-coded into the default configuration files. It
1481 has been assumed that everyone using &my-app; is interested in this
1485 If you want to do without this, there are several approaches you can take:
1486 You can manually undo the many block rules in
1487 <filename>default.action</filename>. Or even easier, just create your own
1488 <filename>default.action</filename> file from scratch without the many ad
1489 blocking rules, and corresponding exceptions. Or lastly, if you are not
1490 concerned about the additional blocks that are done for privacy reasons, you
1491 can very easily over-ride <emphasis>all</emphasis> blocking with the
1492 following very simple rule in your <filename>user.action</filename>:
1496 # Unblock everybody, everywhere
1497 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1498 / # UN-Block *all* URLs</screen>
1501 Or even a more comprehensive reversing of various ad related actions:
1505 # Unblock everybody, everywhere, and turn off appropriate filtering, etc
1506 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> \
1507 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-SIZE">-filter{banners-by-size}</ulink> \
1508 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-LINK">-filter{banners-by-link}</ulink> \
1509 <literal>allow-popups</literal> \
1511 / # UN-Block *all* URLs and allow ads</screen>
1514 This last <quote>action</quote> in this compound statement,
1515 <literal>allow-popups</literal>, is an <ulink
1516 url="../user-manual/actions-file.html#ALIASES">alias</ulink> that disables
1517 various pop-up blocking features.
1521 <sect2 renderas="sect3" id="templates">
1522 <title>How can I have custom template pages, like the
1523 <emphasis>BLOCKED</emphasis> page?</title>
1525 &my-app; <quote>templates</quote> are specialized text files utilized by
1526 &my-app; for various purposes and can easily be modified using any text
1527 editor. All the template pages are installed in a sub-directory appropriately
1528 named: <filename>templates</filename>. Knowing something about HTML syntax
1529 will of course be helpful.
1532 Be forewarned that the default templates are subject to being overwritten
1533 during upgrades. You can, however, create completely new templates,
1534 place them in another directory and specify the alternate path in the main
1535 <filename>config</filename>. For details, have a look at the <ulink
1536 url="../user-manual/config.html#templdir">templdir</ulink> option.
1540 <sect2 renderas="sect3" id="blockall">
1541 <title>How can I remove the <quote>Go There Anyway</quote> link from
1542 the <emphasis>BLOCKED</emphasis> page?</title>
1544 There is more than one way to do it (although Perl is not involved).
1547 Editing the BLOCKED template page (see above) may dissuade some users, but
1548 this method is easily circumvented. Where you need this level of control, you
1549 might want to build &my-app; from source, and disable various features that are
1550 available as compile-time options. You should
1551 <command>configure</command> the sources as follows:
1555 ./configure --disable-toggle --disable-editor --disable-force</screen>
1558 This will create an executable with hard-coded security features so that
1559 &my-app; does not allow easy bypassing of blocked sites, or changing the
1560 current configuration via any connected user's web browser.
1563 Finally, all of these features can also be toggled on/off via options in
1564 <application>Privoxy's</application> main <ulink
1565 url="../user-manual/config.html#ACCESS-CONTROL">config</ulink> file which
1566 means you don't have to recompile anything.
1572 <!-- ~ End section ~ -->
1575 <!-- ~~~~~ New section ~~~~~ -->
1577 <sect1 id="misc"><title>Miscellaneous</title>
1579 <sect2 renderas="sect3" id="slowsme">
1580 <title>How much does Privoxy slow my browsing down? This
1581 has to add extra time to browsing.</title>
1583 How much of an impact depends on many things, including the CPU of the host
1584 system, how aggressive the configuration is, which specific actions are being triggered,
1585 the size of the page, the bandwidth of the connection, etc.
1588 Overall, it should not slow you down any in real terms, and may actually help
1589 speed things up since ads, banners and other junk are not typically being
1590 retrieved and displayed. The actual processing time required by
1591 <application>Privoxy</application> itself for each page, is relatively small
1592 in the overall scheme of things, and happens very quickly. This is typically
1593 more than offset by time saved not downloading and rendering ad images and
1594 other junk content (if ad blocking is being used).
1598 <quote>Filtering</quote> content via the <literal><ulink
1599 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> or
1601 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1602 actions may cause a perceived slowdown, since the entire document
1603 needs to be buffered before displaying. And on very large documents,
1604 filtering may have some measurable impact. How much depends on the page size,
1605 the actual definition of the filter(s), etc. See below. Most other actions
1606 have little to no impact on speed.
1609 Also, when filtering is enabled but zlib support isn't available, compression
1610 is often disabled (see <ulink
1611 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>).
1612 This can have an impact on speed as well, although it's probably smaller than
1613 you might think. Again, the page size, etc. will determine how much of an impact.
1619 <sect2 renderas="sect3" id="loadingtimes"><title>I notice considerable
1620 delays in page requests. What's wrong?</title>
1622 If you use any <literal><ulink
1623 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> action,
1624 such as filtering banners by size, web-bugs etc, or the <literal><ulink
1625 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1626 action, the entire document must be loaded into memory in order for the filtering
1627 mechanism to work, and nothing is sent to the browser during this time.
1630 The loading time typically does not really change much in real numbers, but
1631 the feeling is different, because most browsers are able to start rendering
1632 incomplete content, giving the user a feeling of "it works". This effect is
1633 more noticeable on slower dialup connections. Extremely large documents
1634 may have some impact on the time to load the page where there is filtering
1635 being done. But overall, the difference should be very minimal. If there is a
1636 big impact, then probably some other situation is contributing (like
1637 anti-virus software).
1640 Filtering is automatically disabled for inappropriate MIME types. But note
1641 that if the web server mis-reports the MIME type, then content that should
1642 not be filtered, could be. <application>Privoxy</application> only knows how
1643 to differentiate filterable content because of the MIME type as reported by
1644 the server, or because of some configuration setting that enables/disables
1649 <sect2 renderas="sect3" id="configurl"><title>What are "http://config.privoxy.org/" and
1650 "http://p.p/"?</title>
1652 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink> is the
1653 address of <application>Privoxy</application>'s built-in user interface, and
1654 <ulink url="http://p.p/">http://p.p/</ulink> is a shortcut for it.
1657 Since <application>Privoxy</application> sits between your web browser and the Internet,
1658 it can simply intercept requests for these addresses and answer them with its built-in
1659 <quote>web server</quote>.
1662 This also makes for a good test for your browser configuration: If entering the
1663 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
1664 takes you to a page saying <quote>This is Privoxy ...</quote>, everything is OK.
1665 If you get a page saying <quote>Privoxy is not working</quote> instead, then
1666 your browser didn't use <application>Privoxy</application> for the request,
1667 hence it could not be intercepted, and you have accessed the <emphasis>real</emphasis>
1668 web site at config.privoxy.org.
1671 Note that config.privoxy.org resolves to a public IP address.
1672 If you use config.privoxy.org as ping or traceroute target you will
1673 reach the system on the Internet (Privoxy can't intercept ICMP requests).
1674 If you want to ping the system Privoxy runs on,
1675 you should use its IP address or local DNS name (if it has got one).
1681 out of date 09/02/06 HB
1682 <sect2 renderas="sect3" id="blocklist"><title>Do you still maintain the blocklists?</title>
1684 No. The patterns for blocking now reside (among other things) in the <ulink
1685 url="../user-manual/actions-file.html">actions files</ulink>, which are
1686 actively maintained instead. See next question ...
1690 <sect2 renderas="sect3" id="newads"><title>How can I submit new ads, or report
1693 Please see the <link linkend="contact">Contact section</link> for
1694 various ways to interact with the developers.
1699 <sect2 renderas="sect3" id="newads2"><title>If I do submit missed ads, will
1700 they be included in future updates?</title>
1702 Whether such submissions are eventually included in the
1703 <filename>default.action</filename> configuration file depends on how
1704 significant the issue is. We of course want to address any potential
1705 problem with major, high-profile sites such as <citetitle>Google</citetitle>,
1706 <citetitle>Yahoo</citetitle>, etc. Any site with global or regional reach,
1707 has a good chance of being a candidate. But at the other end of the spectrum
1708 are any number of smaller, low-profile sites such as for local clubs or
1709 schools. Since their reach and impact are much less, they are best handled by
1710 inclusion in the user's <filename>user.action</filename>, and thus would be
1711 unlikely to be included.
1717 <sect2 renderas="sect3" id="noonecares"><title>Why doesn't anyone answer my support
1720 Rest assured that it has been read and considered. Why it is not answered,
1721 could be for various reasons, including no one has a good answer for it, no
1722 one has had time to yet investigate it thoroughly, it has been reported
1723 numerous times already, or because not enough information was provided to help
1724 us help you. Your efforts are not wasted, and we do appreciate them.
1730 <sect2 renderas="sect3" id="ip"><title>How can I hide my IP address?</title>
1732 If you run both the browser and &my-app; locally, you cannot hide your IP
1733 address with <application>Privoxy</application> or ultimately any other
1734 software alone. The server needs to know your IP address so that it knows
1735 where to send the responses back.
1738 There are many publicly usable "anonymous" proxies out there, which
1739 provide a further level of indirection between you and the web server.
1742 However, these proxies are called "anonymous" because you don't need
1743 to authenticate, not because they would offer any real anonymity.
1744 Most of them will log your IP address and make it available to the
1745 authorities in case you violate the law of the country they run in. In fact
1746 you can't even rule out that some of them only exist to *collect* information
1747 on (those suspicious) people with a more than average preference for privacy.
1750 If you want to hide your IP address from most adversaries,
1751 you should consider chaining <application>Privoxy</application>
1752 with <ulink url="https://www.torproject.org/">Tor</ulink>.
1753 The configuration details can be found in
1754 <ulink url="#TOR">How do I use <application>Privoxy</application> together
1755 with <application>Tor</application> section</ulink>
1760 <sect2 renderas="sect3" id="anonforsure">
1761 <title>Can Privoxy guarantee I am anonymous?</title>
1763 No. Your chances of remaining anonymous are improved, but unless you
1764 <ulink url="#TOR">chain <application>Privoxy</application> with <application>Tor</application></ulink>
1765 or a similar proxy and know what you're doing when it comes to configuring
1766 the rest of your system, you should assume that everything you do
1767 on the Web can be traced back to you.
1770 <application>Privoxy</application> can remove various information about you,
1771 and allows <emphasis>you</emphasis> more freedom to decide which sites
1772 you can trust, and what details you want to reveal. But it neither
1773 hides your IP address, nor can it guarantee that the rest of the system
1774 behaves correctly. There are several possibilities how a web sites can find
1775 out who you are, even if you are using a strict <application>Privoxy</application>
1776 configuration and chained it with <application>Tor</application>.
1779 Most of <application>Privoxy's</application> privacy-enhancing features can be easily subverted
1780 by an insecure browser configuration, therefore you should use a browser that can
1781 be configured to only execute code from trusted sites, and be careful which sites you trust.
1782 For example there is no point in having <application>Privoxy</application>
1783 modify the User-Agent header, if websites can get all the information they want
1784 through JavaScript, ActiveX, Flash, Java etc.
1787 A few browsers disclose the user's email address in certain situations, such
1788 as when transferring a file by FTP. <application>Privoxy</application>
1789 does not filter FTP. If you need this feature, or are concerned about the
1790 mail handler of your browser disclosing your email address, you might
1791 consider products such as <application>NSClean</application>.
1794 Browsers available only as binaries could use non-standard headers to give
1795 out any information they can have access to: see the manufacturer's license
1796 agreement. It's impossible to anticipate and prevent every breach of privacy
1797 that might occur. The professionally paranoid prefer browsers available as
1798 source code, because anticipating their behavior is easier. Trust the source,
1804 <sect2 renderas="sect3" id="proxytest">
1805 <title>A test site says I am not using a Proxy.</title>
1807 Good! Actually, they are probably testing for some other kinds of proxies.
1808 Hiding yourself completely would require additional steps.
1812 <sect2 renderas="sect3" id="tor"><title>How do I use Privoxy
1813 together with Tor?</title>
1815 Before you configure <application>Privoxy</application> to use
1816 <ulink url="https://www.torproject.org/">Tor</ulink>,
1817 please follow the <citetitle>User Manual</citetitle> chapters
1818 <ulink url="../user-manual/installation.html">2. Installation</ulink> and
1819 <ulink url="../user-manual/startup.html">5. Startup</ulink> to make sure
1820 <application>Privoxy</application> itself is setup correctly.
1823 If it is, refer to <ulink url="https://www.torproject.org/documentation.html">Tor's
1824 extensive documentation</ulink> to learn how to install <application>Tor</application>,
1825 and make sure <application>Tor</application>'s logfile says that
1826 <quote>Tor has successfully opened a circuit</quote> and it
1827 <quote>looks like client functionality is working</quote>.
1830 If either <application>Tor</application> or <application>Privoxy</application>
1831 isn't working, their combination most likely will neither. Testing them on their
1832 own will also help you to direct problem reports to the right audience.
1833 If <application>Privoxy</application> isn't working, don't bother the
1834 <application>Tor</application> developers. If <application>Tor</application>
1835 isn't working, don't send bug reports to the <application>Privoxy</application> Team.
1838 If you verified that <application>Privoxy</application> and <application>Tor</application>
1839 are working, it is time to connect them. As far as <application>Privoxy</application>
1840 is concerned, <application>Tor</application> is just another proxy that can be reached
1841 by socks4, socks4a and socks5. Most likely you are interested in <application>Tor</application>
1842 to increase your anonymity level, therefore you should use socks5, to make sure DNS
1843 requests are done through <application>Tor</application> and thus invisible to your
1844 local network. Using socks4a would work too, but with socks5 you get more precise error
1849 <application>Privoxy's</application>
1850 <ulink url="../user-manual/config.html">main configuration file</ulink>
1851 is already prepared for <application>Tor</application>, if you are using a
1852 default <application>Tor</application> configuration and run it on the same
1853 system as &my-app;, you just have to edit the
1854 <ulink url="../user-manual/config.html#FORWARDING">forwarding section</ulink>
1855 and uncomment the line:
1859 # forward-socks5t / 127.0.0.1:9050 .
1863 Note that if you got Tor through one of the bundles, you may
1864 have to change the port from 9050 to 9150 (or even another one).
1865 For details, please check the documentation on the
1866 <ulink url="https://torproject.org/">Tor website</ulink>.
1870 This is enough to reach the Internet, but additionally you might want to
1871 uncomment the following forward rules, to make sure your local network is still
1872 reachable through Privoxy:
1876 # forward 192.168.*.*/ .
1877 # forward 10.*.*.*/ .
1878 # forward 127.*.*.*/ .
1882 Unencrypted connections to systems in these address ranges will
1883 be as (un)secure as the local network is, but the alternative is
1884 that your browser can't reach the network at all. Then again,
1885 that may actually be desired and if you don't know for sure
1886 that your browser has to be able to reach the local network,
1887 there's no reason to allow it.
1890 If you want your browser to be able to reach servers in your local
1891 network by using their names, you will need additional exceptions
1892 that look like this:
1896 # forward localhost/ .
1900 Save the modified configuration file and open
1901 <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1902 in your browser, confirm that <application>Privoxy</application> has reloaded its configuration
1903 and that there are no other forward lines, unless you know that you need them. If everything looks good,
1905 <ulink url="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#IsMyConnectionPrivate">Tor
1906 Faq 4.2</ulink> to learn how to verify that you are really using <application>Tor</application>.
1909 Afterward, please take the time to at least skim through the rest
1910 of <application>Tor's</application> documentation. Make sure you understand
1911 what <application>Tor</application> does, why it is no replacement for
1912 application level security, and why you probably don't want to
1913 use it for unencrypted logins.
1917 <sect2 renderas="sect3" id="sitebreak">
1918 <title>Might some things break because header information or
1919 content is being altered?</title>
1922 Definitely. It is common for sites to use browser type, browser version,
1923 HTTP header content, and various other techniques in order to dynamically
1924 decide what to display and how to display it. What you see, and what I see,
1925 might be very different. There are many, many ways that this can be handled,
1926 so having hard and fast rules, is tricky.
1930 The <quote>User-Agent</quote> is sometimes used in this way to identify
1931 the browser, and adjust content accordingly.
1935 Also, different browsers use different encodings of non-English
1936 characters, certain web servers convert pages on-the-fly according to the
1937 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1938 operating system or browser manufacturer causes some sites in these languages
1939 to be garbled; Surfers to Eastern European sites should change it to
1940 something closer. And then some page access counters work by looking at the
1941 <quote>Referer</quote> header; they may fail or break if unavailable. The
1942 weather maps of Intellicast have been blocked by their server when no
1943 <quote>Referer</quote> or cookie is provided, is another example. (But you
1944 can forge both headers without giving information away). There are
1945 many other ways things can go wrong when trying to fool a web server. The
1946 results of which could inadvertently cause pages to load incorrectly,
1947 partially, or even not at all. And there may be no obvious clues as to just
1948 what went wrong, or why. Nowhere will there be a message that says
1949 <quote><emphasis>Turn off <literal>fast-redirects</literal> or else!</emphasis>
1954 Similar thoughts apply to modifying JavaScript, and, to a lesser degree,
1959 If you have problems with a site, you will have to adjust your configuration
1960 accordingly. Cookies are probably the most likely adjustment that may
1961 be required, but by no means the only one.
1967 <sect2 renderas="sect3" id="caching">
1968 <title>Can Privoxy act as a <quote>caching</quote> proxy to
1969 speed up web browsing?</title>
1971 No, it does not have this ability at all. You want something like
1972 <ulink url="http://www.squid-cache.org/">Squid</ulink> or
1973 <ulink url="http://www.pps.jussieu.fr/~jch/software/polipo/">Polipo</ulink> for this.
1974 And, yes, before you ask, <application>Privoxy</application> can co-exist
1975 with other kinds of proxies like <application>Squid</application>.
1976 See the <ulink url="../user-manual/config.html#FORWARDING">forwarding
1977 chapter</ulink> in the <ulink url="../user-manual/index.html">user
1978 manual</ulink> for details.
1982 <sect2 renderas="sect3" id="firewall">
1983 <title>What about as a firewall? Can Privoxy protect me?</title>
1985 Not in the way you mean, or in the way some firewall vendors claim they can.
1986 <application>Privoxy</application> can help protect your privacy, but can't
1987 protect your system from intrusion attempts. It is, of course, perfectly possible
1988 to use <emphasis>both</emphasis>.
1992 <sect2 renderas="sect3" id="wasted">
1993 <title>I have large empty spaces / a checkerboard pattern now where
1994 ads used to be. Why?</title>
1996 It is technically possible to eliminate banners and ads in a way that frees
1997 their allocated page space. This could easily be done by blocking with
1998 <application>Privoxy's</application> filters,
1999 and eliminating the <emphasis>entire</emphasis> image references from the
2003 But, this would consume considerably more CPU resources (IOW, slow things
2004 down), would likely destroy the layout of some web pages which rely on the
2005 banners utilizing a certain amount of page space, and might fail in other
2006 cases, where the screen space is reserved (e.g. by HTML tables for instance).
2007 Also, making ads and banners disappear without any trace complicates
2008 troubleshooting, and would sooner or later be problematic.
2011 The better alternative is to instead let them stay, and block the resulting
2012 requests for the banners themselves as is now the case. This leaves either
2013 empty space, or the familiar checkerboard pattern.
2016 So the developers won't support this in the default configuration, but you
2017 can of course define appropriate filters yourself to achieve this.
2021 <sect2 renderas="sect3" id="ssl">
2022 <title>How can Privoxy filter Secure (HTTPS) URLs?</title>
2024 Since secure HTTP connections are encrypted SSL sessions between your browser
2025 and the secure site, and are meant to be reliably <emphasis>secure</emphasis>,
2026 there is little that <application>Privoxy</application> can do but hand the raw
2027 gibberish data though from one end to the other unprocessed.
2030 The only exception to this is blocking by host patterns, as the client needs
2031 to tell <application>Privoxy</application> the name of the remote server,
2032 so that <application>Privoxy</application> can establish the connection.
2033 If that name matches a host-only pattern, the connection will be blocked.
2036 As far as ad blocking is concerned, this is less of a restriction than it may
2037 seem, since ad sources are often identifiable by the host name, and often
2038 the banners to be placed in an encrypted page come unencrypted nonetheless
2039 for efficiency reasons, which exposes them to the full power of
2040 <application>Privoxy</application>'s ad blocking.
2043 <quote>Content cookies</quote> (those that are embedded in the actual HTML or
2044 JS page content, see <literal><ulink
2045 url="../user-manual/actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</ulink></literal>),
2046 in an SSL transaction will be impossible to block under these conditions.
2047 Fortunately, this does not seem to be a very common scenario since most
2048 cookies come by traditional means.
2053 <sect2 renderas="sect3" id="secure">
2054 <title>Privoxy runs as a <quote>server</quote>. How
2055 secure is it? Do I need to take any special precautions?</title>
2057 On Unix-like systems, <application>Privoxy</application> can run as a non-privileged
2058 user, which is how we recommend it be run. Also, by default
2059 <application>Privoxy</application> listens to requests from <quote>localhost</quote>
2063 The server aspect of <application>Privoxy</application> is not itself directly
2064 exposed to the Internet in this configuration. If you want to have
2065 <application>Privoxy</application> serve as a LAN proxy, this will have to
2066 be opened up to allow for LAN requests. In this case, we'd recommend
2067 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
2068 <application>Privoxy</application> configuration file and check all <ulink
2069 url="../user-manual/config.html#ACCESS-CONTROL">access control and security
2070 options</ulink>. All LAN hosts can then use this as their proxy address
2071 in the browser proxy configuration, but <application>Privoxy</application>
2072 will not listen on any external interfaces. ACLs can be defined in addition,
2073 and using a firewall is always good too. Better safe than sorry.
2078 <sect2 renderas="sect3" id="turnoff">
2079 <title>Can I temporarily disable Privoxy?</title>
2081 &my-app; doesn't have a transparent proxy mode,
2082 but you can toggle off blocking and content filtering.
2085 The easiest way to do that is to point your browser
2086 to the remote toggle URL: <ulink
2087 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>.
2090 See the <ulink url="../user-manual/appendix.html#BOOKMARKLETS">Bookmarklets section</ulink>
2091 of the <citetitle>User Manual</citetitle> for an easy way to access this
2092 feature. Note that this is a feature that may need to be enabled in the main
2093 <filename>config</filename> file.
2098 <sect2 renderas="sect3" id="reallyoff">
2099 <title>When <quote>disabled</quote> is Privoxy totally
2100 out of the picture?</title>
2102 No, this just means all optional filtering and actions are disabled.
2103 <application>Privoxy</application> is still acting as a proxy, but just
2104 doing less of the things that <application>Privoxy</application> would
2105 normally be expected to do. It is still a <quote>middle-man</quote> in
2106 the interaction between your browser and web sites. See below to bypass
2111 <sect2 renderas="sect3" id="turnoff2">
2112 <title>How can I tell Privoxy to totally ignore certain sites?</title>
2114 Bypassing a proxy, or proxying based on arbitrary criteria, is purely a browser
2115 configuration issue, not a &my-app; issue. Modern browsers typically do have
2116 settings for not proxying certain sites. Check your browser's help files.
2121 <sect2 renderas="sect3" id="crunch">
2122 <title>My logs show Privoxy <quote>crunches</quote>
2123 ads, but also its own internal CGI pages. What is a <quote>crunch</quote>?</title>
2125 A <quote>crunch</quote> simply means <application>Privoxy</application> intercepted
2126 <emphasis>something</emphasis>, nothing more. Often this is indeed ads or
2127 banners, but <application>Privoxy</application> uses the same mechanism for
2128 trapping requests for its own internal pages. For instance, a request for
2129 <application>Privoxy's</application> configuration page at: <ulink
2130 url="http://config.privoxy.org">http://config.privoxy.org</ulink>, is
2131 intercepted (i.e. it does not go out to the 'net), and the familiar CGI
2132 configuration is returned to the browser, and the log consequently will show
2133 a <quote>crunch</quote>.
2136 Since version 3.0.7, Privoxy will also log the crunch reason.
2137 If you are using an older version you might want to upgrade.
2141 <sect2 renderas="sect3" id="downloads">
2142 <title>Can Privoxy affect files that I download
2143 from a webserver? FTP server?</title>
2145 From the webserver's perspective, there is no difference between
2146 viewing a document (i.e. a page), and downloading a file. The same is true of
2147 <application>Privoxy</application>. If there is a match for a <literal><ulink
2148 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> pattern,
2149 it will still be blocked, and of course this is obvious.
2152 Filtering is potentially more of a concern since the results are not always
2153 so obvious, and the effects of filtering are there whether the file is simply
2154 viewed, or downloaded. And potentially whether the content is some obnoxious
2155 advertisement, or Mr. Jimmy's latest/greatest source code jewel. Of course,
2156 one of these presumably is <quote>bad</quote> content that we don't want, and
2157 the other is <quote>good</quote> content that we do want.
2158 <application>Privoxy</application> is blind to the differences, and can only
2159 distinguish <quote>good from bad</quote> by the configuration parameters
2160 <emphasis>we</emphasis> give it.
2163 <application>Privoxy</application> knows the differences in files according
2164 to the <quote>Content Type</quote> as reported by the webserver. If this is
2165 reported accurately (e.g. <quote>application/zip</quote> for a zip archive),
2166 then <application>Privoxy</application> knows to ignore these where
2167 appropriate. <application>Privoxy</application> potentially can filter HTML
2168 as well as plain text documents, subject to configuration parameters of
2169 course. Also, documents that are of an unknown type (generally assumed to be
2170 <quote>text/plain</quote>) can be filtered, as will those that might be
2171 incorrectly reported by the webserver. If such a file is a downloaded file
2172 that is intended to be saved to disk, then any content that might have been
2173 altered by filtering, will be saved too, for these (probably rare) cases.
2176 Note that versions later than 3.0.2 do NOT filter document types reported as
2177 <quote>text/plain</quote>. Prior to this, <application>Privoxy</application>
2178 did filter this document type.
2181 In short, filtering is <quote>ON</quote> if a) the content type as reported
2182 by the webserver is appropriate <emphasis>and</emphasis> b) the configuration
2183 allows it (or at least does not disallow it). That's it. There is no magic
2184 cookie anywhere to say this is <quote>good</quote> and this is
2185 <quote>bad</quote>. It's the configuration that lets it all happen or not.
2188 If you download text files, you probably do not want these to be filtered,
2189 particularly if the content is source code, or other critical content. Source
2190 code sometimes might be mistaken for Javascript (i.e. the kind that might
2191 open a pop-up window). It is recommended to turn off filtering for download
2192 sites (particularly if the content may be plain text files and you are using
2193 version 3.0.2 or earlier) in your <filename>user.action</filename> file. And
2194 also, for any site or page where making <emphasis>any</emphasis> changes at
2195 all to the content is to be avoided.
2198 <application>Privoxy</application> does not do FTP at all, only HTTP
2199 and HTTPS (SSL) protocols.
2203 <sect2 renderas="sect3" id="downloads2">
2204 <title>I just downloaded a Perl script, and Privoxy
2205 altered it! Yikes, what is wrong!</title>
2211 <sect2 renderas="sect3" id="hostsfile">
2212 <title>Should I continue to use a <quote>HOSTS</quote> file for ad-blocking?</title>
2214 One time-tested technique to defeat common ads is to trick the local DNS
2215 system by giving a phony IP address for the ad generator in the local
2216 <filename>HOSTS</filename> file, typically using <literal>127.0.0.1</literal>, aka
2217 <literal>localhost</literal>. This effectively blocks the ad.
2220 There is no reason to use this technique in conjunction with
2221 <application>Privoxy</application>. <application>Privoxy</application>
2222 does essentially the same thing, much more elegantly and with much more
2223 flexibility. A large <filename>HOSTS</filename> file, in fact, not only
2224 duplicates effort, but may get in the way and seriously slow down your system.
2225 It is recommended to remove such entries from your <filename>HOSTS</filename> file. If you think
2226 your hosts list is neglected by <application>Privoxy's </application>
2227 configuration, consider adding your list to your <filename>user.action</filename> file:
2234 ads.galore.example.com
2235 etc.example.com</screen>
2239 <sect2 renderas="sect3" id="seealso">
2240 <title>Where can I find more information about Privoxy
2241 and related issues?</title>
2242 <!-- Include seealso.sgml boilerplate: -->
2244 <!-- end boilerplate -->
2249 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
2255 <sect2 renderas="sect3" id="microsuck">
2256 <title>I've noticed that Privoxy changes <quote>Microsoft</quote> to
2257 <quote>MicroSuck</quote>! Why are you manipulating my browsing?</title>
2260 We're not. The text substitutions that you are seeing are disabled
2261 in the default configuration as shipped. You have either manually
2262 activated the <quote><literal>fun</literal></quote> filter which
2263 is clearly labeled <quote>Text replacements for subversive browsing
2264 fun!</quote> or you are using an older Privoxy version and have implicitly
2265 activated it by choosing the <quote>Advanced</quote> profile in the
2266 web-based editor. Please upgrade.
2270 <sect2 renderas="sect3" id="valid">
2271 <title>Does Privoxy produce <quote>valid</quote> HTML (or XHTML)?</title>
2274 Privoxy generates HTML in both its own <quote>templates</quote>, and possibly
2275 whenever there are text substitutions via a &my-app; filter. While this
2276 should always conform to the HTML 4.01 specifications, it has not been
2277 validated against this or any other standard.
2281 <sect2 renderas="sect3" id="surprise-privoxy">
2282 <title>How did you manage to get Privoxy on my computer without my consent?</title>
2285 We didn't. We make Privoxy available for download, but we don't go
2286 around installing it on other people's systems behind their back.
2287 If you discover Privoxy running on your system and are sure you didn't
2288 install it yourself, somebody else did. You may not even be running
2289 the real Privoxy, but maybe something else that only pretends to be
2290 Privoxy, or maybe something that is based on the real Privoxy,
2291 but has been modified.
2294 Lately there have been reports of problems with some kind of
2295 "parental control" software based on Privoxy that came preinstalled on
2296 certain <ulink url="https://sourceforge.net/p/ijbswa/bugs/813/">ASUS Netbooks</ulink>.
2297 The problems described are inconsistent with the behaviour of official
2298 Privoxy versions, which suggests that the preinstalled software may
2299 contain vendor modifications that we don't know about and thus can't debug.
2302 Privoxy's <link linkend="copyright">license</link> allows vendor
2303 modifications, but the vendor has to comply with the license,
2304 which involves informing the user about the changes and to make
2305 the changes available under the same license as Privoxy itself.
2308 If you are having trouble with a modified Privoxy version,
2309 please try to talk to whoever made the modifications before
2310 reporting the problem to us. Please also try to convince
2311 whoever made the modifications to talk to us. If you think
2312 somebody gave you a modified Privoxy version without complying
2313 to the license, please let us know.
2321 <!-- ~~~~~ New section ~~~~~ -->
2323 <sect1 id="trouble">
2324 <title>Troubleshooting</title>
2326 <sect2 renderas="sect3" id="refused">
2327 <title>I cannot connect to any websites. Or, I am getting
2328 <quote>connection refused</quote> message with every web page. Why?</title>
2330 There are several possibilities:
2335 <application>Privoxy</application> is not running. Solution: verify
2336 that &my-app; is installed correctly, has not crashed, and is indeed running.
2337 Turn on <application>Privoxy's</application> logging, and look at the logs to see what they say.
2339 <listitem><para>Or your browser is configured for a different port than what
2340 <application>Privoxy</application> is using. Solution: verify that &my-app;
2341 and your browser are set to the same port (<literal>listen-address</literal>).
2343 <listitem><para>Or if using a forwarding rule, you have a configuration problem or a
2344 problem with a host in the forwarding chain. Solution: temporarily alter your
2345 configuration and take the forwarders out of the equation.
2348 Or you have a firewall that is interfering and blocking you. Solution:
2349 try disabling or removing the firewall as a simple test.
2356 <!-- ~~~~~ New section ~~~~~ -->
2357 <sect2 renderas="sect3" id="error503">
2358 <title>Why am I getting a 503 Error (WSAECONNREFUSED) on every page?</title>
2360 More than likely this is a problem with your TCP/IP networking. ZoneAlarm has
2361 been reported to cause this symptom -- even if not running! The solution is
2362 to either fight the ZA configuration, or uninstall ZoneAlarm, and then find
2363 something better behaved in its place. Other personal firewall type products
2364 may cause similar type problems if not configured correctly.
2368 <sect2 renderas="sect3" id="flushit">
2369 <title>I just added a new rule, but the steenkin ad is
2370 still getting through. How?</title>
2372 If the ad had been displayed before you added its URL, it will probably be
2373 held in the browser's cache for some time, so it will be displayed without
2374 the need for any request to the server, and <application>Privoxy</application>
2375 will not be involved. Flush the browser's caches, and then try again.
2379 If this doesn't help, you probably have an error in the rule you
2380 applied. Try pasting the full URL of the offending ad into <ulink
2381 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2382 and see if it really matches your new rule. Blocking ads is like blocking
2383 spam: a lot of tinkering is required to stay ahead of the game. And
2384 remember you need to block the URL of the ad in question, which may be
2385 entirely different from the site URL itself. Most ads are hosted on different
2386 servers than the main site itself. If you right-click on the ad, you should
2387 be able to get all the relevant information you need. Alternately, you can
2388 find the correct URL by looking at <application>Privoxy's</application> logs
2389 (you may need to enable logging in the main config file if its disabled).
2392 Below is a slightly modified real-life log snippet that originates with one
2393 requested URL: <literal>www.example.com</literal> (name of site was changed
2394 for this example, the number of requests is real). You can see in this the
2395 complexity of what goes into making up this one <quote>page</quote>. There
2396 are eight different domains involved here, with thirty two separate URLs
2397 requested in all, making up all manner of images, Shockwave Flash,
2398 JavaScript, CSS stylesheets, scripts, and other related content. Some of this
2399 content is obviously <quote>good</quote> or <quote>bad</quote>, but not all.
2400 Many of the more questionable looking requests, are going to outside domains
2401 that seem to be identifying themselves with suspicious looking names, making
2402 our job a little easier. &my-app; has <quote>crunched</quote> (meaning caught
2403 and BLOCKED) quite a few items in this example, but perhaps missed a few as well.
2408 Request: www.example.com/
2409 Request: www.example.com/favicon.ico
2410 Request: img.example.com/main.css
2411 Request: img.example.com/sr.js
2412 Request: example.betamarker.com/example.html
2413 Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
2414 Request: img.example.com/pb.png
2415 Request: www.google-analytics.com/urchin.js crunch! (Blocked)
2416 Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch! (Blocked)
2417 Request: img.example.com/p.gif
2418 Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch! (Blocked)
2419 Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch! (Blocked)
2420 Request: www.popuptraffic.com/assign.php?l=example crunch! (Blocked)
2421 Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
2422 Request: www.adtrak.net/adx.js crunch! (Blocked)
2423 Request: img.example.com/hbg.gif
2424 Request: img.example.com/example.jpg
2425 Request: img.example.com/mt.png
2426 Request: img.example.com/mm.png
2427 Request: img.example.com/mb.png
2428 Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch! (Blocked)
2429 Request: www.example.com/tracker.js
2430 Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
2431 Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch! (Blocked)
2432 Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch! (Blocked)
2433 Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
2434 Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch! (Blocked)
2435 Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
2436 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch! (Blocked)
2437 Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
2438 Request: 66.70.21.80/img/pixel.gif
2439 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch! (Blocked)
2440 Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
2445 Despite 12 out of 32 requests being blocked, the page looked, and seemed to
2446 behave perfectly <quote>normal</quote> (minus some ads, of course).
2451 <sect2 renderas="sect3" id="badsite">
2452 <title>One of my favorite sites does not work with Privoxy.
2453 What can I do?</title>
2456 First verify that it is indeed a <application>Privoxy</application> problem,
2457 by toggling off <application>Privoxy</application> through <ulink
2458 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
2459 (the toggle feature may need to be enabled in the main
2460 <filename>config</filename>),
2461 and then shift-reloading the problem page (i.e. holding down the shift key
2462 while clicking reload. Alternatively, flush your browser's disk and memory
2467 If the problem went away, we know we have a configuration related problem.
2469 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2470 and paste the full URL of the page in question into the prompt. See which
2471 actions are being applied to the URL, and which matches in which actions
2472 files are responsible for that. It might be helpful also to look at your logs
2473 for this site too, to see what else might be happening (note: logging may need
2474 to be enabled in the main config file). Many sites are
2475 complex and require a number of related pages to help present their content.
2476 Look at what else might be used by the page in question, and what of that
2477 might be <emphasis>required</emphasis>.
2478 Now, armed with this information, go to
2480 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2481 and select the appropriate actions files for editing. </para>
2483 You can now either look for a section which disables the actions that
2484 you suspect to cause the problem and add a pattern for your site there,
2485 or make up a completely new section for your site. In any case, the recommended
2486 way is to disable only the prime suspect, reload the problem page, and only
2487 if the problem persists, disable more and more actions until you have
2488 identified the culprit. You may or may not want to turn the other actions
2489 on again. Remember to flush your browser's caches in between any such changes!
2492 Alternately, if you are comfortable with a text editor, you can accomplish
2493 the same thing by editing the appropriate actions file. Probably the easiest
2494 way to deal with such problems when editing by hand is to add your
2495 site to a <literal>{ fragile }</literal> section in <filename>user.action</filename>,
2496 which is an alias that turns off most <quote>dangerous</quote>
2497 actions, but is also likely to turn off more actions then needed, and thus lower
2498 your privacy and protection more than necessary,
2501 Troubleshooting actions is discussed in more detail in the <ulink
2502 url="../user-manual/appendix.html#ACTIONSANAT">User Manual appendix,
2503 Troubleshooting: the Anatomy of an Action</ulink>.
2504 There is also an <ulink
2505 url="../user-manual/actions-file.html#ACT-EXAMPLES">actions tutorial</ulink>
2506 with general configuration information and examples.
2509 As a last resort, you can always see if your browser has a setting that will
2510 bypass the proxy setting for selective sites. Modern browsers can do this.
2516 <!-- ~~~~~ New section ~~~~~ -->
2517 <sect2 id="dun" renderas="sect3">
2518 <title>After installing Privoxy, I have to log in
2519 every time I start IE. What gives?</title>
2522 This is a quirk that affects the installation of
2523 <application>Privoxy</application>, in conjunction with Internet Explorer and
2524 Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may
2525 appear to be corrupted or invalid DUN settings, or passwords.
2529 When setting up an NT based Windows system with
2530 <application>Privoxy</application> you may find that things do not seem to be
2531 doing what you expect. When you set your system up you will probably have set
2532 up Internet Connection Sharing (ICS) with Dial up Networking (DUN) when
2533 logged in with administrator privileges. You will probably have made this DUN
2534 connection available to other accounts that you may have set-up on your
2535 system. E.g. Mum or Dad sets up the system and makes accounts suitably
2536 configured for the kids.
2540 When setting up <application>Privoxy</application> in this environment you
2541 will have to alter the proxy set-up of Internet Explorer (IE) for the
2542 specific DUN connection on which you wish to use
2543 <application>Privoxy</application>. When you do this the ICS DUN set-up
2544 becomes user specific. In this instance you will see no difference if you
2545 change the DUN connection under the account used to set-up the connection.
2546 However when you do this from another user you will notice that the DUN
2547 connection changes to make available to "Me only". You will also find that
2548 you have to store the password under each different user!
2552 The reason for this is that each user's set-up for IE is user specific. Each
2553 set-up DUN connection and each LAN connection in IE store the settings for
2554 each user individually. As such this enforces individual configurations
2555 rather than common ones. Hence the first time you use a DUN connection after
2556 re-booting your system it may not perform as you expect, and prompt you for
2557 the password. Just set and save the password again and all should be OK.
2561 [Thanks to Ray Griffith for this submission.]
2566 <!-- ~~~~~ New section ~~~~~ -->
2567 <sect2 id="ftp" renderas="sect3">
2568 <title>I cannot connect to any FTP sites. Privoxy
2569 is blocking me.</title>
2571 <application>Privoxy</application> cannot act as a proxy for FTP traffic,
2572 so do not configure your browser to use <application>Privoxy</application>
2573 as an FTP proxy. The same is true for <emphasis>any protocol other than HTTP
2574 or HTTPS (SSL)</emphasis>.
2577 Most browsers understand FTP as well as HTTP. If you connect to a site, with
2578 a URL like <literal>ftp://ftp.example.com</literal>, your browser is making
2579 an FTP connection, and not a HTTP connection. So while your browser may
2580 speak FTP, <application>Privoxy</application> does not, and cannot proxy
2584 To complicate matters, some systems may have a generic <quote>proxy</quote>
2585 setting, which will enable various protocols, including
2586 <emphasis>both</emphasis> HTTP and FTP proxying! So it is possible to
2587 accidentally enable FTP proxying in these cases. And of course, if this
2588 happens, <application>Privoxy</application> will indeed cause problems since
2589 it does not know FTP. <![%p-newstuff;[Newer version will give a sane error
2590 message if a FTP connection is attempted.]]> Just disable the FTP setting
2591 and all will be well again.
2594 Will <application>Privoxy</application> ever proxy FTP traffic? Unlikely.
2595 There just is not much reason, and the work to make this happen is more than
2600 <!-- ~~~~~ New section ~~~~~ -->
2601 <sect2 id="macosxie" renderas="sect3">
2602 <title>In Mac OS X, I can't configure Microsoft Internet Explorer to use
2603 Privoxy as the HTTP proxy.</title>
2605 Microsoft Internet Explorer (in versions like 5.1) respects system-wide
2606 network settings. In order to change the HTTP proxy, open System
2607 Preferences, and click on the Network icon. In the settings pane that
2608 comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox
2609 is checked and enter <literal>127.0.0.1</literal> in the entry field.
2610 Enter <literal>8118</literal> in the Port field. The next time you start
2611 IE, it should reflect these values.
2615 <!-- ~~~~~ New section ~~~~~ -->
2616 <sect2 renderas="sect3" id="macosxuninstall">
2617 <title>In Mac OS X, I dragged the Privoxy folder to the trash in order to
2618 uninstall it. Now the finder tells me I don't have sufficient privileges to
2619 empty the trash.</title>
2621 Note: This ONLY applies to privoxy 3.0.6 and earlier.
2624 Just dragging the <application>Privoxy</application> folder to the trash is
2625 not enough to delete it. <application>Privoxy</application> supplies an
2626 <application>uninstall.command</application> file that takes care of
2627 these details. Open the trash, drag the <application>uninstall.command</application>
2628 file out of the trash and double-click on it. You will be prompted for
2629 confirmation and the administration password.
2632 The trash may still appear full after this command; emptying the trash
2633 from the desktop should make it appear empty again.
2637 <!-- ~~~~~ New section ~~~~~ -->
2638 <sect2 renderas="sect3" id="macosximages">
2639 <title>In Mac OS X Panther (10.3), images often fail to load and/or I
2640 experience random delays in page loading. I'm using
2641 <literal>localhost</literal> as my browser's proxy setting.</title>
2643 We believe this is due to an IPv6-related bug in Mac OS X, but don't fully
2644 understand the issue yet. In any case, changing the proxy setting to
2645 <literal>127.0.0.1</literal> instead of <literal>localhost</literal>
2646 works around the problem.
2650 <!-- ~~~~~ New section ~~~~~ -->
2651 <sect2 renderas="sect3" id="macosxaccountdeletion">
2652 <title>I just upgraded to Mac OS X 10.9 (Mavericks) and now &my-app; has stopped
2655 The upgrade process to Mac OS X Mavericks (10.9) from an earlier version of OS
2656 X deletes all user accounts that are either not part of OS X itself or are
2657 not interactive user accounts (ones you log in with). Since, for the sake of
2658 security, &my-app; runs as a non-privileged user that is created by its
2659 installer (_privoxy), it can no longer start up once that account gets deleted.
2660 The solution is to perform a complete uninstall using the supplied
2661 <application>uninstall.command</application> script (either back up your
2662 configuration files or select to not have the uninstaller remove them when it
2663 prompts you) and then reinstall &my-app; using the installer package and merge
2664 in your configuration.
2668 <sect2 renderas="sect3" id="nohostname">
2669 <title>My logs show many <quote>Unable to get my own hostname</quote> lines.
2672 <application>Privoxy</application> tries to get the hostname of the system
2673 its running on from the IP address of the system interface it is bound to
2674 (from the <filename>config</filename> file
2675 <emphasis>listen-address</emphasis> setting). If the system cannot supply
2676 this information, <application>Privoxy</application> logs this condition.
2679 Typically, this would be considered a minor system configuration error. It is
2680 not a fatal error to <application>Privoxy</application> however, but may
2681 result in a much slower response from <application>Privoxy</application> on
2682 some platforms due to DNS timeouts.
2685 This can be caused by a problem with the local <filename>hosts</filename>
2686 file. If this file has been changed from the original, try reverting it to
2687 see if that helps. Make sure whatever name(s) are used for the local system,
2688 that they resolve both ways.
2691 You should also be able to work around the problem with the
2692 <ulink url="../user-manual/config.html#HOSTNAME">hostname option</ulink>.
2696 <sect2 renderas="sect3" id="inuse">
2697 <title>When I try to launch Privoxy, I get an
2698 error message <quote>port 8118 is already in use</quote> (or similar wording).
2701 Port 8118 is <application>Privoxy's</application> default TCP
2702 <quote>listening</quote> port. Typically this message would mean that there
2703 is already one instance of <application>Privoxy</application> running, and
2704 your system is actually trying to start a second
2705 <application>Privoxy</application> on the same port, which will not work.
2706 (You can have multiple instances but they must be assigned different ports.)
2707 How and why this might happen varies from platform to platform, but you need
2708 to check your installation and start-up procedures.
2712 <sect2 renderas="sect3" id="demoronizer">
2714 Pages with UTF-8 fonts are garbled.
2717 This may be the result of an overly aggressive filter. The filters that
2718 are enabled in the default configuration aren't expected to cause problems
2719 like this. If you enabled the <quote>demoronizer</quote> filter, please
2720 try temporarily disabling it.
2723 If that doesn't help, temporarily disable all filters to see if another
2724 filter could be the culprit. If the problem disappears, enable the filters
2725 one by one, until the problem reappears and the offending filter is found.
2728 Once the problem-causing filter is known, it can be fixed or disabled.
2731 Upgrading <application>Privoxy</application>, or going to the most recent
2732 <filename>default.action</filename> file available from <ulink
2733 url="https://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>
2734 might be worth a try, too.
2738 <sect2 renderas="sect3" id="demoronizer2">
2740 Why are binary files (such as images) corrupted when Privoxy
2744 This may also be caused by an (<link linkend="DEMORONIZER">overly aggressive
2745 filter</link> in conjunction with a web server that is misreporting the content
2746 type. By default binary files are exempted from
2747 <application>Privoxy's</application> filtering
2748 (unless the web server by mistake says the file is something else).
2752 <sect2 renderas="sect3" id="demoronizer3">
2754 What is the <quote>demoronizer</quote> and why is it there?
2757 The original demoronizer was a Perl script that cleaned up HTML pages which
2758 were created with certain Microsoft products. MS has used proprietary extensions
2759 to standardized font encodings (ISO 8859-1), which has caused problems for pages
2760 that are viewed with non-Microsoft products (and are expecting to see a
2761 standard set of fonts). The demoronizer corrected these errors so the pages
2762 displayed correctly. <application>Privoxy</application> borrowed from this
2763 script, introducing a filter based on the original demoronizer, which in turn could
2764 correct these errors on the fly.
2767 But this is only needed in some situations, and will cause serious problems in some
2771 If you are using Microsoft products, you do not need it. If you need to view
2772 pages with UTF-8 characters (such as Cyrillic or Chinese), then it will
2773 cause corruption of the fonts, and thus <emphasis>should not be on</emphasis>.
2776 On the other hand, if you use non-Microsoft products, and you occasionally
2777 notice weird characters on pages, you might want to try it.
2781 <sect2 renderas="sect3" id="windowopen">
2783 Why do I keep seeing <quote>PrivoxyWindowOpen()</quote> in raw source code?
2786 <application>Privoxy</application> is attempting to disable malicious
2787 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink>
2788 in this case, with the <literal>unsolicited-popups</literal>
2789 filter. <application>Privoxy</application> cannot tell very well
2790 <quote>good</quote> code snippets from <quote>bad</quote> code snippets.
2793 If you see this in HTML source, and the page displays without problems, then
2794 this is good, and likely some pop-up window was disabled. If you see this
2795 where it is causing a problem, such as a downloaded program source code file,
2796 then you should set an exception for this site or page such that the
2797 integrity of the page stays in tact by disabling all filtering.
2801 <sect2 renderas="sect3" id="dnserrors">
2803 I am getting too many DNS errors like <quote>404 No Such Domain</quote>. Why
2804 can't Privoxy do this better?
2807 There are potentially several factors here. First of all, the DNS resolution
2808 is done by the underlying operating system -- not
2809 <application>Privoxy</application> itself. <application>Privoxy</application>
2810 merely initiates the process and hands it off, and then later reports
2811 whatever the outcome was and tries to give a coherent message if there seems
2812 to be a problem. In some cases, this might otherwise be mitigated by the
2813 browser itself which might try some work-arounds and alternate approaches (e.g
2814 adding <quote>www.</quote> to the URL).
2817 In other cases, if <application>Privoxy</application> is being chained
2818 with another proxy, this could complicate the issue, and cause undue
2819 delays and timeouts. In the case of a <quote>socks4a</quote> proxy, the socks
2820 server handles all the DNS. <application>Privoxy</application> would just be
2821 the <quote>messenger</quote> which is reporting whatever problem occurred
2822 downstream, and not the root cause of the error.
2826 In any case, versions newer than 3.0.3 include various improvements to help
2827 <application>Privoxy</application> better handle these cases.
2831 <sect2 renderas="sect3" id="allcpu">
2833 At one site Privoxy just hangs, and starts taking
2834 all CPU. Why is this?
2837 This is probably a manifestation of the <quote>100% cpu</quote> problem that
2838 occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines
2839 are in the raw HTML source of the page, and the browser just ignores them. But the
2840 pattern matching in <application>Privoxy's</application> page filtering
2841 mechanism is trying to match against absurdly long strings and this becomes
2842 very CPU-intensive, taking a long, long time to complete.
2845 Until a better solution comes along, disable filtering on these pages,
2846 particularly the <literal>js-annoyances</literal> and
2847 <literal>unsolicited-popups</literal> filters. If you run into this problem
2848 with a recent &my-app; version, please send a problem report.
2852 <sect2 renderas="sect3" id="slowcrawl">
2853 <title>I just installed Privoxy, and all my
2854 browsing has slowed to a crawl. What gives? </title>
2856 This should not happen, and for the overwhelming number of users world-wide,
2857 it does not happen. I would suspect some inadvertent interaction of software
2858 components such as anti-virus software, spyware protectors, personal
2859 firewalls or similar components. Try disabling (or uninstalling) these one
2860 at a time and see if that helps. Either way, if you are using a
2861 recent &my-app; version, please report the problem.
2865 <sect2 renderas="sect3" id="preventcomp">
2866 <title>Why do my filters work on some sites but not on others? </title>
2868 It's probably due to compression. It is a common practice for web servers to
2869 send their content <quote>compressed</quote> in order to speed things up, and
2870 then let the browser <quote>uncompress</quote> them. When compiled with zlib support
2871 &my-app; can decompress content before filtering, otherwise you may want to enable
2873 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>.
2876 As of &my-app; 3.0.9, zlib support is enabled in the default builds.
2881 <sect2 renderas="sect3" id="ssl-warnings">
2882 <title>On some HTTPS sites my browser warns me about unauthenticated content,
2883 the URL bar doesn't get highlighted and the lock symbol appears to be broken.
2884 What's going on?</title>
2886 Probably the browser is requesting ads through HTTPS and &my-app;
2887 is blocking the requests. Privoxy's error messages are delivered
2888 unencrypted and while it's obvious for the browser that the HTTPS
2889 request is already blocked by the proxy, some warn about unauthenticated
2893 To work around the problem you can redirect those requests to an invalid
2894 local address instead of blocking them. While the redirects aren't
2895 encrypted either, many browsers don't care. They simply follow the
2896 redirect, fail to reach a server and display an error message instead
2900 To do that, enable logging to figure out which requests get blocked by
2901 &my-app; and add the hosts (no path patterns) to a section like this:
2906 {+redirect{http://127.0.0.1:0/} -block -limit-connect}
2912 Additionally you have to configure your browser to contact
2913 <quote>127.0.0.1:0</quote> directly (instead of through &my-app;).
2916 To add a proxy exception in <application>Mozilla Firefox</application>
2917 open the <quote>Preferences</quote>, click the <quote>Settings</quote>
2918 button located on the <quote>Network</quote> tab in the <quote>Advanced</quote>
2919 section, and add <quote>127.0.0.1:0</quote> in the <quote>No Proxy for:</quote>
2925 <sect2 renderas="sect3" id="se-linux">
2926 <title>I get selinux error messages. How can I fix this?</title>
2928 Please report the problem to the creator of your selinux policies.
2931 The problem is that some selinux policy writers aren't familiar
2932 with the application they are trying to <quote>secure</quote> and
2933 thus create policies that make no sense.
2936 In <application>Privoxy's</application> case the problem usually
2937 is that the policy only allows outgoing connections for certain
2938 destination ports (e.g. 80 and 443). While this may cover the
2939 standard ports, websites occasionally use other ports as well.
2940 This isn't a security problem and therefore <application>Privoxy's</application>
2941 default configuration doesn't block these requests.
2944 If you really want to block these ports (and don't be able
2945 to load websites that don't use standard ports), you should
2946 configure Privoxy to block these ports as well, so it doesn't
2947 trigger the selinux warnings.
2952 <sect2 renderas="sect3" id="gentoo-ricers">
2953 <title>I compiled &my-app; with Gentoo's portage and it appears to be very slow. Why?</title>
2955 Probably you unintentionally compiled &my-app; without threading support
2956 in which case requests have to be serialized and only one can be served
2960 Check your <quote>USE</quote> flags and make sure they include
2961 <quote>threads</quote>. If they don't, add the flag and rebuild &my-app;.
2964 If you compiled &my-app; with threading support (on POSIX-based systems),
2965 the <quote>Conditional #defines</quote> section on <ulink
2966 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2967 will list <quote>FEATURE_PTHREAD</quote> as <quote>enabled</quote>.
2971 <sect2 renderas="sect3" id="tainted-sockets">
2972 <title>What are tainted sockets and how do I prevent them?</title>
2974 &my-app; marks sockets as tainted when it can't use them to
2975 serve additional requests.
2976 This does not necessarily mean that something went wrong and
2977 information about tainted sockets is only logged if connection
2978 debugging is enabled (debug 2).
2981 For example server sockets that were used for CONNECT requests
2982 (which are used to tunnel https:// requests) are considered tainted
2983 once the client closed its connection to &my-app;.
2984 Technically &my-app; could keep the connection to the server open,
2985 but the server would not accept requests that do not belong to the
2986 previous TLS/SSL session (and the client may even have terminated
2990 Server sockets are also marked tainted when a client requests a
2991 resource, but closes the connection before &my-app; has completely
2992 received (and forwarded) the resource to the client.
2993 In this case the server would (probably) accept additional requests,
2994 but &my-app; could not get the response without completely reading
2995 the leftovers from the previous response.
2998 These are just two examples, there are currently a bit more than
2999 25 scenarios in which a socket is considered tainted.
3002 While sockets can also be marked tainted as a result of a technical
3003 problem that may be worth fixing, the problem will be explicitly
3008 <sect2 renderas="sect3" id="pcre-stack-limit">
3009 <title>After adding my custom filters, &my-app; crashes when visitting certain websites</title>
3011 This can happen if your custom filters require more memory than &my-app;
3013 Usually the problem is that the operating system enforces a stack size limit
3014 that isn't sufficient.
3017 Unless the problem occurs with the filters available in the default configuration,
3018 this is not considered a Privoxy bug.
3021 To prevent the crashes you can rewrite your filter to use less ressources,
3022 increase the relevant memory limit or recompile pcre to use less stack space.
3023 For details please see the
3024 <ulink url="http://pcre.org/original/doc/html/pcrestack.html">pcrestack man page</ulink>
3025 and the documentation of your operating system.
3031 <!-- ~~~~~ New section ~~~~~ -->
3032 <sect1 id="contact"><title>Contacting the developers, Bug Reporting and Feature Requests</title>
3033 <!-- Include contacting.sgml -->
3035 <!-- end contacting -->
3038 <!-- ~~~~~ New section ~~~~~ -->
3039 <sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
3041 <!-- Include copyright.sgml -->
3047 Portions of this document are <quote>borrowed</quote> from the original
3048 <application>Junkbuster</application> (tm) FAQ, and modified as
3049 appropriate for <application>Privoxy</application>.
3052 <!-- ~~~~~ New section ~~~~~ -->
3053 <sect2><title>License</title>
3054 <!-- Include copyright.sgml: -->
3056 <!-- end copyright -->
3058 <!-- ~ End section ~ -->
3060 <!-- ~~~~~ New section ~~~~~ -->
3061 <sect2><title>History</title>
3062 <!-- Include history.sgml -->
3068 <!-- ~ End section ~ -->
3071 <!-- ~~~~~ New section ~~~~~ -->
3073 <sect1 id="seealso"><title>See also</title>
3075 <!-- Include seealso.sgml -->
3085 This program is free software; you can redistribute it
3086 and/or modify it under the terms of the GNU General
3087 Public License as published by the Free Software
3088 Foundation; either version 2 of the License, or (at
3089 your option) any later version.
3091 This program is distributed in the hope that it will
3092 be useful, but WITHOUT ANY WARRANTY; without even the
3093 implied warranty of MERCHANTABILITY or FITNESS FOR A
3094 PARTICULAR PURPOSE. See the GNU General Public
3095 License for more details.
3097 The GNU General Public License should be included with
3098 this file. If not, you can view it at
3099 http://www.gnu.org/copyleft/gpl.html
3100 or write to the Free Software Foundation, Inc.,
3101 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
projects / privoxy.git / blob