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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 2.129 2016/07/28 08:25:33 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 2.129 2016/07/28 08:25:33 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. Logos are served from
590 our server, no requests are made to the sponsor website unless
591 the links are being used.
594 The details may change over time but changes will only affect new sponsors
595 (or existing sponsors that explicitly agreed to the changes).
598 If you want to become a sponsor, please contact
599 <ulink url="mailto:fk@fabiankeil.de">Fabian Keil</ulink>.
600 New sponsors are only accepted if no developer objects.
608 <!-- ~~~~~ New section ~~~~~ -->
610 <sect1 id="installation"><title>Installation</title>
612 <sect2 renderas="sect3" id="whichbrowsers">
613 <title>Which browsers are supported by Privoxy?</title>
615 Any browser that can be configured to use a proxy, which
616 should be virtually all browsers, including
617 <application>Firefox</application>, <application>Internet
618 Explorer</application>, <application>Opera</application>, and
619 <application>Safari</application> among others.
620 Direct browser support is not an absolute requirement since
621 <application>Privoxy</application> runs as a separate application and talks
622 to the browser in the standardized HTTP protocol, just like a web server
627 <sect2 renderas="sect3" id="whichos">
628 <title>Which operating systems are supported?</title>
630 Include supported.sgml here:
635 <sect2 renderas="sect3" id="email-client">
636 <title>Can I use Privoxy with my email client?</title>
638 As long as there is some way to set a HTTP proxy for the client, then yes,
639 any application can be used, whether it is strictly speaking a
640 <quote>browser</quote> or not. Though this may not be the best approach for
641 dealing with some of the common abuses of HTML in email. See <link
642 linkend="outlook">How can I configure <application>Privoxy</application>
643 with <application>Outlook</application>?</link> below for more on
647 Be aware that HTML email presents a number of unique security and privacy
648 related issues, that can require advanced skills to overcome. The developers
649 recommend using email clients that can be configured to convert HTML to plain
650 text for these reasons.
654 <!-- Nobody is going to still be doing this!
655 <sect2 renderas="sect3" id="newinstall"><title>Can I install
656 Privoxy over Junkbuster?</title>
658 We recommend you un-install <application>Junkbuster</application>
659 first to minimize conflicts and confusion. You may want to
660 save your old configuration files for future reference. The configuration
661 files and syntax have substantially changed, so you will need to manually
662 port your old patterns. See the <ulink url="../user-manual/upgradersnote.html">note
663 to upgraders</ulink> and <ulink url="../user-manual/installation.html">installation
664 chapter</ulink> in the <ulink url="../user-manual/index.html">User Manual</ulink>
668 Note: Some installers may automatically un-install
669 <application>Junkbuster</application>, if present!
675 <sect2 renderas="sect3" id="firststep">
676 <title>I just installed Privoxy. Is there anything
677 special I have to do now?</title>
680 All browsers should be told to use <application>Privoxy</application>
681 as a proxy by specifying the correct proxy address and port number
682 in the appropriate configuration area for the browser. It's possible
683 to combine &my-app; with a packet filter to intercept HTTP requests
684 even if the client isn't explicitly configured to use &my-app;,
685 but where possible, configuring the client is recommended. See
686 <ulink url="../user-manual/startup.html">the User Manual for more
687 details</ulink>. You should also flush your browser's memory and disk
688 cache to get rid of any cached junk items, and remove any stored
689 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>.
695 <sect2 renderas="sect3" id="localhost"><title>What is the proxy address of Privoxy?</title>
697 If you set up the <application>Privoxy</application> to run on
698 the computer you browse from (rather than your ISP's server or some
699 networked computer on a LAN), the proxy will be on <literal>127.0.0.1</literal>
700 (sometimes referred to as <quote>localhost</quote>,
701 which is the special name used by every computer on the Internet to refer
702 to itself) and the port will be 8118 (unless you used the <ulink
703 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
704 config option to tell <application>Privoxy</application> to run on
708 When configuring your browser's proxy settings you typically enter
709 the word <quote>localhost</quote> or the IP address <quote>127.0.0.1</quote>
710 in the boxes next to <quote>HTTP</quote> and <quote>Secure</quote> (HTTPS) and
711 then the number <quote>8118</quote> for <quote>port</quote>.
712 This tells your browser to send all web requests to <application>Privoxy</application>
713 instead of directly to the Internet.
716 <application>Privoxy</application> can also be used to proxy for
717 a Local Area Network. In this case, your would enter either the IP
718 address of the LAN host where <application>Privoxy</application>
719 is running, or the equivalent hostname, e.g. <literal>192.168.1.1</literal>.
720 Port assignment would be same as above. Note that
721 <application>Privoxy</application> doesn't listen on any LAN interfaces by
725 <application>Privoxy</application> does not currently handle
726 any other protocols such as FTP, SMTP, IM, IRC, ICQ, etc.
730 <sect2 renderas="sect3" id="nothing">
731 <title>I just installed Privoxy, and nothing is happening.
732 All the ads are there. What's wrong?</title>
735 Did you configure your browser to use <application>Privoxy</application>
736 as a proxy? It does not sound like it. See above. You might also try flushing
737 the browser's caches to force a full re-reading of pages. You can verify
738 that <application>Privoxy</application> is running, and your browser
739 is correctly configured by entering the special URL:
740 <ulink url="http://p.p/">http://p.p/</ulink>.
741 <!-- Use http://p.p/ instead of http://config.privoxy.org/ here because
742 of potential redirect caching problem (see next Q). -->
743 This should take you to a page titled <quote>This is Privoxy..</quote> with
744 access to <application>Privoxy's</application> internal configuration.
745 If you see this, then you are good to go. If you receive a page saying
746 <quote>Privoxy is not running</quote>, then the browser is not set up to use
747 your <application>Privoxy</application> installation.
748 If you receive anything else (probably nothing at all), it could either
749 be that the browser is not set up correctly, or that
750 <application>Privoxy</application> is not running at all. Check the <ulink
751 url="../user-manual/config.html#LOGFILE">log file</ulink>. For instructions
752 on starting <application>Privoxy</application> and browser configuration,
753 see the <ulink url="https://www.privoxy.org/user-manual/startup.html">chapter
754 on starting <application>Privoxy</application></ulink> in the
755 <ulink url="https://www.privoxy.org/user-manual/">User Manual</ulink>.
760 <sect2 renderas="sect3" id="notused">
761 <title>I get a <quote>Privoxy is not being used</quote> dummy page although
762 Privoxy is running and being used.</title>
765 First, make sure that Privoxy is <emphasis>really</emphasis> running and
766 being used by visiting <ulink url="http://p.p/">http://p.p/</ulink>. You
767 should see the <application>Privoxy</application> main page. If not, see
768 the <ulink url="https://www.privoxy.org/user-manual/startup.html">chapter
769 on starting <application>Privoxy</application></ulink> in the
770 <ulink url="https://www.privoxy.org/user-manual/">User Manual</ulink>.
774 Now if <ulink url="http://p.p/">http://p.p/</ulink> works for you, but
775 other parts of <application>Privoxy</application>'s web interface show
776 the dummy page, your browser has cached a redirection it encountered before
777 <application>Privoxy</application> was being used. You need to clear your
778 browser's cache. Note that shift-reloading the dummy page won't help, since
779 that'll only refresh the dummy page, not the redirection that lead you there.
783 The procedure for clearing the cache varies from browser to browser. For
784 example, <application>Mozilla/Netscape</application> users would click
785 <guibutton>Edit</guibutton> --> <guibutton>Preferences</guibutton> -->
786 <guibutton>Advanced</guibutton> --> <guibutton>Cache</guibutton> and
787 then click both <quote><guibutton>Clear Memory Cache</guibutton></quote>
788 and <quote><guibutton>Clear Disk Cache</guibutton></quote>.
789 In some <application>Firefox</application> versions it's
790 <guibutton>Tools</guibutton> --> <guibutton>Options</guibutton> -->
791 <guibutton>Privacy</guibutton> --> <guibutton>Cache</guibutton> and
792 then click <quote><guibutton>Clear Cache Now</guibutton></quote>.
793 <!-- In my Firefox versions it's the Netscape way. fk 2007-11-19-->
800 <!-- ~~~~~ New section ~~~~~ -->
802 <sect1 id="configuration"><title>Configuration</title>
803 <sect2 renderas="sect3" id="actionsfile">
804 <title>What exactly is an <quote>actions</quote> file?</title>
807 &my-app; utilizes the concept of <quote>
808 <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink></quote>
809 that are used to manipulate and control web page data.
810 <ulink url="../user-manual/actions-file.html">Actions files</ulink>
811 are where these <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink>
812 that <application>Privoxy</application> could take while processing a certain
813 request, are configured. Typically, you would define a set of default actions
814 that apply globally to all URLs, then add exceptions to these defaults where needed.
815 There is a wide array of actions available that give the user a high degree
816 of control and flexibility on how to process each and every web page.
820 Actions can be defined on a <ulink
821 url="../user-manual/actions-file.html#AF-PATTERNS">URL pattern</ulink> basis, i.e.
822 for single URLs, whole web sites, groups or parts thereof etc. Actions can also be
823 grouped together and then applied to requests matching one or more patterns.
824 There are many possible actions that might apply to any given site. As an example,
825 if you are blocking <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
826 as one of your default actions, but need to accept cookies from a given site,
827 you would need to define an exception for this site in one of your actions
828 files, preferably in <filename>user.action</filename>.
833 <sect2 renderas="sect3" id="actionss">
834 <title>The <quote>actions</quote> concept confuses me. Please list
835 some of these <quote>actions</quote>.</title>
837 For a comprehensive discussion of the actions concept, please refer
838 to the <ulink url="../user-manual/actions-file.html">actions file
839 chapter</ulink> in the <ulink url="../user-manual/index.html">User
840 Manual</ulink>. It includes a <ulink
841 url="../user-manual/actions-file.html#ACTIONS">list of all actions</ulink>
842 and an <ulink url="../user-manual/actions-file.html#ACT-EXAMPLES">actions
843 file tutorial</ulink> to get you started.
848 <sect2 renderas="sect3" id="actconfig">
849 <title>How are actions files configured? What is the easiest
850 way to do this?</title>
853 Actions files are just text files in a special syntax and can be edited
854 with a text editor. But probably the easiest way is to access
855 <application>Privoxy</application>'s user interface with your web browser
856 at <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
857 (Shortcut: <ulink url="http://p.p/">http://p.p/</ulink>) and then select
858 <quote><ulink url="http://config.privoxy.org/show-status">View &
859 change the current configuration</ulink></quote> from the menu. Note
860 that this feature must be explicitly enabled in the main config file
862 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
867 <sect2 renderas="sect3">
868 <title>There are several different <quote>actions</quote> files. What are
869 the differences?</title>
871 Please have a look at the <ulink url="../user-manual/actions-file.html">the actions chapter</ulink>
872 in the <ulink url="../user-manual/index.html">User Manual</ulink> for a detailed explanation.
877 <sect2 renderas="sect3" id="getupdates"><title>Where can I get updated Actions Files?</title>
879 Based on your feedback and the continuing development, updates of
880 <filename>default.action</filename> will be
881 made available from time to time on the <ulink
882 url="https://sourceforge.net/project/showfiles.php?group_id=11118">files section</ulink> of
883 our <ulink url="https://sourceforge.net/projects/ijbswa/">project page</ulink>.
887 If you wish to receive an email notification whenever we release updates of
888 <application>Privoxy</application> or the actions file, <ulink
889 url="https://lists.privoxy.org/mailman/listinfo/privoxy-announce">subscribe
890 to our announce mailing list</ulink>, privoxy-announce@lists.privoxy.org.
895 <sect2 renderas="sect3" id="newconfig"><title>Can I use my old config files?</title>
897 The syntax and purpose of configuration files has remained roughly the
898 same throughout the 3.x series, but backwards compatibility is not guaranteed.
899 Also each release contains updated, <quote>improved</quote> versions and it is
900 therefore strongly recommended to install the newer configuration files
901 and merge back your modifications.
905 <sect2 renderas="sect3" id="difficult">
906 <title>Why is the configuration so complicated?</title>
908 <quote>Complicated</quote> is in the eye of the beholder.
911 Privoxy is currently mainly written by and for people who are already
912 familiar with the underlying concepts like regular expressions, HTTP and HTML,
913 or are willing to become familiar with them to be able to get the most
914 out of a powerful and flexible tool such as Privoxy.
917 While everybody is expected to be able to get a Privoxy default installation
918 up and running, fine-tuning requires a certain amount of background
919 information and Privoxy's documentation mainly concentrates on the
920 Privoxy-specific parts while only providing references to the rest.
923 If you or anyone you know has the skills, time and energy to
924 reduce the barrier of entry, please <link linkend="participate">get involved</link>.
928 <sect2 renderas="sect3" id="yahoo"><title>How can I make my Yahoo/Hotmail/Gmail account work?</title>
930 The default configuration shouldn't impact the usability of any of these services.
931 It may, however, make all <ulink
932 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
933 temporary, so that your browser will forget your
934 login credentials in between browser sessions. If you would like not to have to log
935 in manually each time you access those websites, simply turn off all cookie handling
936 for them in the <filename>user.action</filename> file. An example for yahoo might
940 <screen># Allow all cookies for Yahoo login:
942 { -<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> }
943 .login.yahoo.com</screen>
946 These kinds of sites are often quite complex and heavy with
947 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> and
948 thus <quote>fragile</quote>. So if <emphasis>still</emphasis> a problem,
950 url="../user-manual/actions-file.html#ALIASES">alias</ulink> just for such
954 <screen># Gmail is a _fragile_ site:
956 { <literal>fragile</literal> }
958 mail.google.com</screen>
961 Be sure to flush your browser's caches whenever making these kinds of
962 changes, just to make sure the changes <quote>take</quote>.
965 Make sure the domain, host and path are appropriate as well. Your browser can
966 tell you where you are specifically and you should use that information for
967 your configuration settings. Note that above it is not referenced as
968 <literal>gmail.com</literal>, which is a valid domain name.
973 <sect2 renderas="sect3" id="configfiles"> <title>What's the difference between the
974 <quote>Cautious</quote>, <quote>Medium</quote> and <quote>Advanced</quote> defaults?</title>
976 Configuring <application>Privoxy</application> is not entirely trivial. To
977 help you get started, we provide you with three different default action
978 <quote>profiles</quote> in the web based actions file editor at <ulink
979 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
980 See the <ulink url="../user-manual/actions-file.html"><citetitle>User
981 Manual</citetitle></ulink> for a list of actions, and how the default
986 Where the defaults are likely to break some sites, exceptions for
987 known popular <quote>problem</quote> sites are included, but in
988 general, the more aggressive your default settings are, the more exceptions
989 you will have to make later. New users are best to start off in
990 <quote>Cautious</quote> setting. This is safest and will have the fewest
991 problems. See the <ulink
992 url="../user-manual/index.html"><citetitle>User Manual</citetitle></ulink>
993 for a more detailed discussion.
997 It should be noted that the <quote>Advanced</quote> profile (formerly known
998 as the <quote>Adventuresome</quote> profile) is more
999 aggressive, and will make use of some of
1000 <application>Privoxy's</application> advanced features. Use at your own risk!
1005 <sect2 renderas="sect3" id="browseconfig"> <title>Why can I change the configuration
1006 with a browser? Does that not raise security issues?</title>
1008 It may seem strange that regular users can edit the config files with their
1009 browsers, although the whole <filename>/etc/privoxy</filename> hierarchy
1010 belongs to the user <quote>privoxy</quote>, with only 644 permissions.
1013 When you use the browser-based editor, <application>Privoxy</application>
1014 itself is writing to the config files. Because
1015 <application>Privoxy</application> is running as the user <quote>privoxy</quote>,
1016 it can update its own config files.
1019 If you run <application>Privoxy</application> for multiple untrusted users (e.g. in
1020 a LAN) or aren't entirely in control of your own browser, you will probably want
1021 to make sure that the web-based editor and remote toggle features are
1022 <quote>off</quote> by setting <quote><literal><ulink
1023 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>
1024 0</literal></quote> and <quote><literal><ulink
1025 url="../user-manual/config.html#ENABLE-REMOTE-TOGGLE">enable-remote-toggle</ulink>
1026 0</literal></quote> in the <ulink url="../user-manual/config.html">main configuration file</ulink>.
1029 As of &my-app; 3.0.7 these options are disabled by default.
1034 <sect2 renderas="sect3" id="filterfile">
1035 <title>What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>?</title>
1037 The <ulink url="../user-manual/filter-file.html"><filename>default.filter</filename></ulink>
1038 file is where <emphasis>filters</emphasis> as supplied by the developers are defined.
1039 Filters are a special subset of actions that can be used to modify or
1040 remove web page content or headers on the fly. Content filters can
1041 be applied to <emphasis>anything</emphasis> in the page source,
1042 header filters can be applied to either server or client headers.
1043 Regular expressions are used to accomplish this.
1046 There are a number of pre-defined filters to deal with common annoyances. The
1047 filters are only defined here, to invoke them, you need to use the
1049 url="../user-manual/actions-file.html#FILTER"><literal>filter</literal>
1050 action</ulink> in one of the actions files. Content filtering is automatically
1051 disabled for inappropriate MIME types, but if you know better than Privoxy
1052 what should or should not be filtered you can filter any content you like.
1056 <emphasis>not</emphasis> be confused with <ulink
1057 url="../user-manual/actions-file.html#BLOCK"><literal>blocks</literal></ulink>, which
1058 is a completely different action, and is more typically used to block ads and
1063 If you are familiar with regular expressions, and HTML, you can look at
1064 the provided <filename>default.filter</filename> with a text editor and define
1065 your own filters. This is potentially a very powerful feature, but
1066 requires some expertise in both regular expressions and HTML/HTTP.
1067 <![%p-newstuff;[ You should
1068 place any modifications to the default filters, or any new ones you create
1069 in a separate file, such as <filename>user.filter</filename>, so they won't
1070 be overwritten during upgrades.
1071 The ability to define multiple filter files
1072 in <filename>config</filename> is a new feature as of v. 3.0.5.]]>
1076 There is no GUI editor option for this part of the configuration,
1077 but you can disable/enable the various pre-defined filters of the included
1078 <filename>default.filter</filename> file with the <ulink
1079 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1080 Note that the custom actions editor must be explicitly enabled in
1081 the main config file (see <ulink
1082 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
1086 If you intend to develop your own filters, you might want to have a look at
1088 url="https://www.fabiankeil.de/sourcecode/pft/">Privoxy-Filter-Test</ulink>.
1093 <sect2 renderas="sect3" id="lanconfig">
1094 <title>How can I set up Privoxy to act as a proxy for my
1097 By default, <application>Privoxy</application> only responds to requests
1098 from <literal>127.0.0.1</literal> (localhost). To have it act as a server for
1099 a network, this needs to be changed in the <ulink
1100 url="../user-manual/config.html">main configuration file</ulink>. Look for
1102 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink></literal>
1103 option, which may be commented out with a <quote>#</quote> symbol. Make sure
1104 it is uncommented, and assign it the address of the LAN gateway interface,
1105 and port number to use. Assuming your LAN address is 192.168.1.1 and you
1106 wish to run <application>Privoxy</application> on port 8118, this line
1112 listen-address 192.168.1.1:8118</screen>
1116 Save the file, and restart <application>Privoxy</application>. Configure
1117 all browsers on the network then to use this address and port number.
1121 Alternately, you can have <application>Privoxy</application> listen on
1122 all available interfaces:
1127 listen-address :8118</screen>
1131 And then use <application>Privoxy's</application>
1133 url="../user-manual/config.html#PERMIT-ACCESS">permit-access</ulink>
1134 feature to limit connections. A firewall in this situation is recommended
1139 The above steps should be the same for any TCP network, regardless of
1144 If you run <application>Privoxy</application> on a LAN with untrusted users,
1145 we recommend that you double-check the <ulink
1146 url="../user-manual/config.html#ACCESS-CONTROL">access control and security</ulink>
1153 <sect2 renderas="sect3" id="noseeum">
1154 <title>Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
1156 The replacement for blocked images can be controlled with the <ulink
1157 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1158 action</ulink>. You have the choice of a checkerboard pattern, a transparent 1x1 GIF
1159 image (aka <quote>blank</quote>), or a redirect to a custom image of your choice.
1160 Note that this choice only has effect for images which are blocked as images, i.e.
1161 whose URLs match both a <literal><ulink
1162 url="../user-manual/actions-file.html#HANDLE-AS-IMAGE">handle-as-image</ulink></literal>
1163 <emphasis>and</emphasis> <literal><ulink
1164 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> action.
1167 If you want to see nothing, then change the <ulink
1168 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1169 action</ulink> to <quote>blank</quote>. This can be done by editing the
1170 <filename>user.action</filename> file, or through the <ulink
1171 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1176 <sect2 renderas="sect3" id="whyseeum">
1177 <title>Why would anybody want to see a checkerboard pattern?</title>
1179 Remember that <link linkend="whatsanad">telling which image is an ad and which
1180 isn't</link>, is an educated guess. While we hope that the standard configuration
1181 is rather smart, it will make occasional mistakes. The checkerboard image is visually
1182 decent, and it shows you where images have been blocked, which can be very
1183 helpful in case some navigation aid or otherwise innocent image was
1184 erroneously blocked. It is recommended for new users so they can
1185 <quote>see</quote> what is happening. Some people might also enjoy seeing how
1186 many banners they <emphasis>don't</emphasis> have to see.
1191 <sect2 renderas="sect3" id="blockedbytext">
1192 <title>I see some images being replaced with text
1193 instead of the checkerboard image. Why and how do I get rid of this?</title>
1195 This happens when the banners are not embedded in the HTML code of the
1196 page itself, but in separate HTML (sub)documents that are loaded into (i)frames
1197 or (i)layers, and these external HTML documents are blocked. Being non-images
1198 they get replaced by a substitute HTML page rather than a substitute image,
1199 which wouldn't work out technically, since the browser expects and accepts
1200 only HTML when it has requested an HTML document.
1203 The substitute page adapts to the available space and shows itself as a
1204 miniature two-liner if loaded into small frames, or full-blown with a
1205 large red "BLOCKED" banner if space allows.
1208 If you prefer the banners to be blocked by images, you must see to it that
1209 the HTML documents in which they are embedded are not blocked. Clicking
1210 the <quote>See why</quote> link offered in the substitute page will show
1211 you which rule blocked the page. After changing the rule and un-blocking
1212 the HTML documents, the browser will try to load the actual banner images
1213 and the usual image blocking will (hopefully!) kick in.
1218 <sect2 renderas="sect3" id="srvany">
1219 <title>Can Privoxy run as a service
1220 on Win2K/NT/XP?</title>
1223 Yes. Version 3.0.5 introduces full <application>Windows</application> service
1224 functionality. See <ulink url="../user-manual/installation.html#installation-pack-win">
1225 the <citetitle>User Manual</citetitle></ulink> for details on how to install and configure
1226 <application>Privoxy</application> as a service.
1229 Earlier ]]>3.x versions could run as a system service using <command>srvany.exe</command>.
1230 See the discussion at <ulink
1231 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>,
1232 for details, and a sample configuration.
1237 <sect2 renderas="sect3" id="otherproxy">
1238 <title>How can I make Privoxy work with other proxies?</title>
1240 This can be done and is often useful to combine the benefits of
1241 <application>Privoxy</application> with those of a another proxy,
1242 for example to cache content.
1244 url="../user-manual/config.html#FORWARDING">forwarding chapter</ulink>
1245 in the <ulink url="../user-manual/index.html">User Manual</ulink> which
1246 describes how to do this. If you intend to use Privoxy with Tor,
1247 please also have a look at
1248 <link linkend="TOR">How do I use Privoxy together with Tor</link>.
1252 <sect2 renderas="sect3" id="port-80">
1253 <title>Can I just set Privoxy to use port 80
1254 and thus avoid individual browser configuration?</title>
1257 No, its more complicated than that. This only works with special kinds
1258 of proxies known as <quote>intercepting</quote> proxies
1259 (<link linkend="INTERCEPTING">see below</link>).
1264 <sect2 renderas="sect3" id="transparent">
1265 <title>Can Privoxy run as a <quote>transparent
1266 </quote> proxy?</title>
1268 The whole idea of Privoxy is to modify client requests
1269 and server responses in all sorts of ways and therefore
1270 it's not a transparent proxy as described in
1271 <ulink url="http://tools.ietf.org/html/rfc2616">RFC 2616</ulink>.
1274 However, some people say <quote>transparent proxy</quote> when they
1275 mean <quote>intercepting proxy</quote>. If you are one of them,
1276 please read the <link linkend="INTERCEPTING">next entry</link>.
1281 <sect2 renderas="sect3" id="intercepting">
1282 <title>Can Privoxy run as a <quote>intercepting</quote> proxy?</title>
1284 <application>Privoxy</application> can't intercept traffic itself,
1285 but it can handle requests that where intercepted and redirected
1286 with a packet filter (like <application>PF</application> or
1287 <application>iptables</application>), as long as the <literal>Host</literal>
1291 As the <literal>Host</literal> header is required by HTTP/1.1 and as most
1292 web sites rely on it anyway, this limitation shouldn't be a problem.
1295 Please refer to your packet filter's documentation to learn how to
1296 intercept and redirect traffic into <application>Privoxy</application>.
1297 Afterward you just have to configure <application>Privoxy</application> to
1298 <ulink url="../user-manual/config.html#ACCEPT-INTERCEPTED-REQUESTS">accept
1299 intercepted requests</ulink>.
1304 <sect2 renderas="sect3" id="outlook">
1305 <title>How can I configure Privoxy for use with Outlook?</title>
1307 Versions of <application>Outlook</application> prior to Office 2007, use
1308 <application>Internet Explorer</application> components to both render HTML,
1309 and fetch any HTTP requests that may be embedded in an HTML email. So however
1310 you have <application>Privoxy</application> configured to work with IE, this
1311 configuration should automatically be shared, at least with older version of
1315 Starting with Office 2007, Microsoft is instead using the MS-Word rendering
1316 engine with Outlook. It is unknown whether this can be configured to use a
1318 <!-- FIXME HB 2009-02-15 -->
1322 <sect2 renderas="sect3" id="outlook-more">
1323 <title>How can I have separate rules just for HTML mail?</title>
1325 The short answer is, you can't. <application>Privoxy</application> has no way
1326 of knowing which particular application makes a request, so there is no way to
1327 distinguish between web pages and HTML mail.
1328 <application>Privoxy</application> just blindly proxies all requests. In the
1329 case of <application>Outlook Express</application> (see above), OE uses
1330 IE anyway, and there is no way for <application>Privoxy</application> to ever
1331 be able to distinguish between them (nor could any other proxy type application for
1335 For a good discussion of some of the issues involved (including privacy and
1336 security issues), see
1337 <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>.
1341 <sect2 renderas="sect3" id="sneaky-cookies">
1342 <title>I sometimes notice cookies sneaking through. How?</title>
1345 url="http://en.wikipedia.org/wiki/Browser_cookie">Cookies</ulink> can be
1346 set in several ways. The classic method is via the
1347 <literal>Set-Cookie</literal> HTTP header. This is straightforward, and an
1348 easy one to manipulate, such as the &my-app; concept of
1349 <ulink url="../user-manual/actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</ulink>.
1350 There is also the possibility of using
1351 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> to
1352 set cookies (&my-app; calls these <literal>content-cookies</literal>). This
1353 is trickier because the syntax can vary widely, and thus requires a certain
1354 amount of guesswork. It is not realistic to catch all of these short of
1355 disabling Javascript, which would break many sites. And lastly, if the
1356 cookies are embedded in a HTTPS/SSL secure session via Javascript, they are beyond
1357 <application>Privoxy's</application> reach.
1360 All in all, &my-app; can help manage cookies in general, can help minimize
1361 the loss of privacy posed by cookies, but can't realistically stop all
1366 <sect2 renderas="sect3" id="evil-cookies">
1367 <title>Are all cookies bad? Why?</title>
1369 No, in fact there are many beneficial uses of
1371 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>. Cookies are just a
1372 method that browsers can use to store data between pages, or between browser
1373 sessions. Sometimes there is a good reason for this, and the user's life is a
1374 bit easier as a result. But there is a long history of some websites taking
1375 advantage of this layer of trust, and using the data they glean from you and
1376 your browsing habits for their own purposes, and maybe to your potential
1377 detriment. Such sites are using you and storing their data on your system.
1378 That is why the privacy conscious watch from whom those cookies come, and why
1379 they really <emphasis>need</emphasis> to be there.
1383 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">Wikipedia cookie
1384 definition</ulink> for more.
1388 <sect2 renderas="sect3" id="allow-cookies">
1389 <title>How can I allow permanent cookies for my trusted sites?</title>
1392 There are several actions that relate to cookies. The default behavior is to
1393 allow only <quote>session cookies</quote>, which means the cookies only last
1394 for the current browser session. This eliminates most kinds of abuse related
1395 to cookies. But there may be cases where you want cookies to last.
1398 To disable all cookie actions, so that cookies are allowed unrestricted,
1399 both in and out, for <literal>example.com</literal>:
1403 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
1404 .example.com</screen>
1407 Place the above in <filename>user.action</filename>. Note that some of these may
1408 be off by default anyway, so this might be redundant, but there is no harm
1409 being explicit in what you want to happen. <filename>user.action</filename>
1410 includes an alias for this situation, called
1411 <literal>allow-all-cookies</literal>.
1415 <sect2 renderas="sect3" id="multiples">
1416 <title>Can I have separate configurations for different users?</title>
1418 Each instance of <application>Privoxy</application> has its own
1419 configuration, including such attributes as the TCP port that it listens on.
1420 What you can do is run multiple instances of <application>Privoxy</application>, each with
1422 <ulink url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
1423 configuration setting, and configuration path, and then
1424 each of these can have their own configurations. Think of it as per-port
1428 Simple enough for a few users, but for large installations, consider having
1429 groups of users that might share like configurations.
1433 <sect2 renderas="sect3" id="whitelists">
1434 <title>Can I set-up Privoxy as a whitelist of
1435 <quote>good</quote> sites?</title>
1437 Sure. There are a couple of things you can do for simple white-listing.
1438 Here's one real easy one:
1441 ############################################################
1443 ############################################################
1444 { <ulink url="../user-manual/actions-file.html#BLOCK">+block</ulink> }
1445 / # Block *all* URLs
1447 ############################################################
1449 ############################################################
1450 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1453 games.example.com</screen>
1455 This allows access to only those three sites by first blocking all URLs, and
1456 then subsequently allowing three specific exceptions.
1459 Another approach is <application>Privoxy's</application>
1460 <literal>trustfile</literal> concept, which incorporates the notion of
1461 <quote>trusted referrers</quote>. See the <ulink
1462 url="../user-manual/config.html#TRUSTFILE">Trust documentation</ulink>
1466 These are fairly simple approaches and are not completely foolproof. There
1467 are various other configuration options that should be disabled (described
1468 elsewhere here and in <ulink url="../user-manual/">the User Manual</ulink>)
1469 so that users can't modify their own configuration and easily circumvent the
1474 <sect2 renderas="sect3" id="no-adblock">
1475 <title>How can I turn off ad-blocking?</title>
1477 Ad blocking is achieved through a complex application of various &my-app;
1478 <ulink url="../user-manual/actions-file.html">actions</ulink>. These
1479 actions are deployed against simple images, banners, flash animations,
1480 text pages, JavaScript, pop-ups and pop-unders, etc., so its not as simple as
1481 just turning one or two actions off. The various actions that make up
1482 &my-app; ad blocking are hard-coded into the default configuration files. It
1483 has been assumed that everyone using &my-app; is interested in this
1487 If you want to do without this, there are several approaches you can take:
1488 You can manually undo the many block rules in
1489 <filename>default.action</filename>. Or even easier, just create your own
1490 <filename>default.action</filename> file from scratch without the many ad
1491 blocking rules, and corresponding exceptions. Or lastly, if you are not
1492 concerned about the additional blocks that are done for privacy reasons, you
1493 can very easily over-ride <emphasis>all</emphasis> blocking with the
1494 following very simple rule in your <filename>user.action</filename>:
1498 # Unblock everybody, everywhere
1499 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1500 / # UN-Block *all* URLs</screen>
1503 Or even a more comprehensive reversing of various ad related actions:
1507 # Unblock everybody, everywhere, and turn off appropriate filtering, etc
1508 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> \
1509 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-SIZE">-filter{banners-by-size}</ulink> \
1510 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-LINK">-filter{banners-by-link}</ulink> \
1511 <literal>allow-popups</literal> \
1513 / # UN-Block *all* URLs and allow ads</screen>
1516 This last <quote>action</quote> in this compound statement,
1517 <literal>allow-popups</literal>, is an <ulink
1518 url="../user-manual/actions-file.html#ALIASES">alias</ulink> that disables
1519 various pop-up blocking features.
1523 <sect2 renderas="sect3" id="templates">
1524 <title>How can I have custom template pages, like the
1525 <emphasis>BLOCKED</emphasis> page?</title>
1527 &my-app; <quote>templates</quote> are specialized text files utilized by
1528 &my-app; for various purposes and can easily be modified using any text
1529 editor. All the template pages are installed in a sub-directory appropriately
1530 named: <filename>templates</filename>. Knowing something about HTML syntax
1531 will of course be helpful.
1534 Be forewarned that the default templates are subject to being overwritten
1535 during upgrades. You can, however, create completely new templates,
1536 place them in another directory and specify the alternate path in the main
1537 <filename>config</filename>. For details, have a look at the <ulink
1538 url="../user-manual/config.html#templdir">templdir</ulink> option.
1542 <sect2 renderas="sect3" id="blockall">
1543 <title>How can I remove the <quote>Go There Anyway</quote> link from
1544 the <emphasis>BLOCKED</emphasis> page?</title>
1546 There is more than one way to do it (although Perl is not involved).
1549 Editing the BLOCKED template page (see above) may dissuade some users, but
1550 this method is easily circumvented. Where you need this level of control, you
1551 might want to build &my-app; from source, and disable various features that are
1552 available as compile-time options. You should
1553 <command>configure</command> the sources as follows:
1557 ./configure --disable-toggle --disable-editor --disable-force</screen>
1560 This will create an executable with hard-coded security features so that
1561 &my-app; does not allow easy bypassing of blocked sites, or changing the
1562 current configuration via any connected user's web browser.
1565 Finally, all of these features can also be toggled on/off via options in
1566 <application>Privoxy's</application> main <ulink
1567 url="../user-manual/config.html#ACCESS-CONTROL">config</ulink> file which
1568 means you don't have to recompile anything.
1574 <!-- ~ End section ~ -->
1577 <!-- ~~~~~ New section ~~~~~ -->
1579 <sect1 id="misc"><title>Miscellaneous</title>
1581 <sect2 renderas="sect3" id="slowsme">
1582 <title>How much does Privoxy slow my browsing down? This
1583 has to add extra time to browsing.</title>
1585 How much of an impact depends on many things, including the CPU of the host
1586 system, how aggressive the configuration is, which specific actions are being triggered,
1587 the size of the page, the bandwidth of the connection, etc.
1590 Overall, it should not slow you down any in real terms, and may actually help
1591 speed things up since ads, banners and other junk are not typically being
1592 retrieved and displayed. The actual processing time required by
1593 <application>Privoxy</application> itself for each page, is relatively small
1594 in the overall scheme of things, and happens very quickly. This is typically
1595 more than offset by time saved not downloading and rendering ad images and
1596 other junk content (if ad blocking is being used).
1600 <quote>Filtering</quote> content via the <literal><ulink
1601 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> or
1603 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1604 actions may cause a perceived slowdown, since the entire document
1605 needs to be buffered before displaying. And on very large documents,
1606 filtering may have some measurable impact. How much depends on the page size,
1607 the actual definition of the filter(s), etc. See below. Most other actions
1608 have little to no impact on speed.
1611 Also, when filtering is enabled but zlib support isn't available, compression
1612 is often disabled (see <ulink
1613 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>).
1614 This can have an impact on speed as well, although it's probably smaller than
1615 you might think. Again, the page size, etc. will determine how much of an impact.
1621 <sect2 renderas="sect3" id="loadingtimes"><title>I notice considerable
1622 delays in page requests. What's wrong?</title>
1624 If you use any <literal><ulink
1625 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> action,
1626 such as filtering banners by size, web-bugs etc, or the <literal><ulink
1627 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1628 action, the entire document must be loaded into memory in order for the filtering
1629 mechanism to work, and nothing is sent to the browser during this time.
1632 The loading time typically does not really change much in real numbers, but
1633 the feeling is different, because most browsers are able to start rendering
1634 incomplete content, giving the user a feeling of "it works". This effect is
1635 more noticeable on slower dialup connections. Extremely large documents
1636 may have some impact on the time to load the page where there is filtering
1637 being done. But overall, the difference should be very minimal. If there is a
1638 big impact, then probably some other situation is contributing (like
1639 anti-virus software).
1642 Filtering is automatically disabled for inappropriate MIME types. But note
1643 that if the web server mis-reports the MIME type, then content that should
1644 not be filtered, could be. <application>Privoxy</application> only knows how
1645 to differentiate filterable content because of the MIME type as reported by
1646 the server, or because of some configuration setting that enables/disables
1651 <sect2 renderas="sect3" id="configurl"><title>What are "http://config.privoxy.org/" and
1652 "http://p.p/"?</title>
1654 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink> is the
1655 address of <application>Privoxy</application>'s built-in user interface, and
1656 <ulink url="http://p.p/">http://p.p/</ulink> is a shortcut for it.
1659 Since <application>Privoxy</application> sits between your web browser and the Internet,
1660 it can simply intercept requests for these addresses and answer them with its built-in
1661 <quote>web server</quote>.
1664 This also makes for a good test for your browser configuration: If entering the
1665 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
1666 takes you to a page saying <quote>This is Privoxy ...</quote>, everything is OK.
1667 If you get a page saying <quote>Privoxy is not working</quote> instead, then
1668 your browser didn't use <application>Privoxy</application> for the request,
1669 hence it could not be intercepted, and you have accessed the <emphasis>real</emphasis>
1670 web site at config.privoxy.org.
1673 Note that config.privoxy.org resolves to a public IP address.
1674 If you use config.privoxy.org as ping or traceroute target you will
1675 reach the system on the Internet (Privoxy can't intercept ICMP requests).
1676 If you want to ping the system Privoxy runs on,
1677 you should use its IP address or local DNS name (if it has got one).
1683 out of date 09/02/06 HB
1684 <sect2 renderas="sect3" id="blocklist"><title>Do you still maintain the blocklists?</title>
1686 No. The patterns for blocking now reside (among other things) in the <ulink
1687 url="../user-manual/actions-file.html">actions files</ulink>, which are
1688 actively maintained instead. See next question ...
1692 <sect2 renderas="sect3" id="newads"><title>How can I submit new ads, or report
1695 Please see the <link linkend="contact">Contact section</link> for
1696 various ways to interact with the developers.
1701 <sect2 renderas="sect3" id="newads2"><title>If I do submit missed ads, will
1702 they be included in future updates?</title>
1704 Whether such submissions are eventually included in the
1705 <filename>default.action</filename> configuration file depends on how
1706 significant the issue is. We of course want to address any potential
1707 problem with major, high-profile sites such as <citetitle>Google</citetitle>,
1708 <citetitle>Yahoo</citetitle>, etc. Any site with global or regional reach,
1709 has a good chance of being a candidate. But at the other end of the spectrum
1710 are any number of smaller, low-profile sites such as for local clubs or
1711 schools. Since their reach and impact are much less, they are best handled by
1712 inclusion in the user's <filename>user.action</filename>, and thus would be
1713 unlikely to be included.
1719 <sect2 renderas="sect3" id="noonecares"><title>Why doesn't anyone answer my support
1722 Rest assured that it has been read and considered. Why it is not answered,
1723 could be for various reasons, including no one has a good answer for it, no
1724 one has had time to yet investigate it thoroughly, it has been reported
1725 numerous times already, or because not enough information was provided to help
1726 us help you. Your efforts are not wasted, and we do appreciate them.
1732 <sect2 renderas="sect3" id="ip"><title>How can I hide my IP address?</title>
1734 If you run both the browser and &my-app; locally, you cannot hide your IP
1735 address with <application>Privoxy</application> or ultimately any other
1736 software alone. The server needs to know your IP address so that it knows
1737 where to send the responses back.
1740 There are many publicly usable "anonymous" proxies out there, which
1741 provide a further level of indirection between you and the web server.
1744 However, these proxies are called "anonymous" because you don't need
1745 to authenticate, not because they would offer any real anonymity.
1746 Most of them will log your IP address and make it available to the
1747 authorities in case you violate the law of the country they run in. In fact
1748 you can't even rule out that some of them only exist to *collect* information
1749 on (those suspicious) people with a more than average preference for privacy.
1752 If you want to hide your IP address from most adversaries,
1753 you should consider chaining <application>Privoxy</application>
1754 with <ulink url="https://www.torproject.org/">Tor</ulink>.
1755 The configuration details can be found in
1756 <ulink url="#TOR">How do I use <application>Privoxy</application> together
1757 with <application>Tor</application> section</ulink>
1762 <sect2 renderas="sect3" id="anonforsure">
1763 <title>Can Privoxy guarantee I am anonymous?</title>
1765 No. Your chances of remaining anonymous are improved, but unless you
1766 <ulink url="#TOR">chain <application>Privoxy</application> with <application>Tor</application></ulink>
1767 or a similar proxy and know what you're doing when it comes to configuring
1768 the rest of your system, you should assume that everything you do
1769 on the Web can be traced back to you.
1772 <application>Privoxy</application> can remove various information about you,
1773 and allows <emphasis>you</emphasis> more freedom to decide which sites
1774 you can trust, and what details you want to reveal. But it neither
1775 hides your IP address, nor can it guarantee that the rest of the system
1776 behaves correctly. There are several possibilities how a web sites can find
1777 out who you are, even if you are using a strict <application>Privoxy</application>
1778 configuration and chained it with <application>Tor</application>.
1781 Most of <application>Privoxy's</application> privacy-enhancing features can be easily subverted
1782 by an insecure browser configuration, therefore you should use a browser that can
1783 be configured to only execute code from trusted sites, and be careful which sites you trust.
1784 For example there is no point in having <application>Privoxy</application>
1785 modify the User-Agent header, if websites can get all the information they want
1786 through JavaScript, ActiveX, Flash, Java etc.
1789 A few browsers disclose the user's email address in certain situations, such
1790 as when transferring a file by FTP. <application>Privoxy</application>
1791 does not filter FTP. If you need this feature, or are concerned about the
1792 mail handler of your browser disclosing your email address, you might
1793 consider products such as <application>NSClean</application>.
1796 Browsers available only as binaries could use non-standard headers to give
1797 out any information they can have access to: see the manufacturer's license
1798 agreement. It's impossible to anticipate and prevent every breach of privacy
1799 that might occur. The professionally paranoid prefer browsers available as
1800 source code, because anticipating their behavior is easier. Trust the source,
1806 <sect2 renderas="sect3" id="proxytest">
1807 <title>A test site says I am not using a Proxy.</title>
1809 Good! Actually, they are probably testing for some other kinds of proxies.
1810 Hiding yourself completely would require additional steps.
1814 <sect2 renderas="sect3" id="tor"><title>How do I use Privoxy
1815 together with Tor?</title>
1817 Before you configure <application>Privoxy</application> to use
1818 <ulink url="https://www.torproject.org/">Tor</ulink>,
1819 please follow the <citetitle>User Manual</citetitle> chapters
1820 <ulink url="../user-manual/installation.html">2. Installation</ulink> and
1821 <ulink url="../user-manual/startup.html">5. Startup</ulink> to make sure
1822 <application>Privoxy</application> itself is setup correctly.
1825 If it is, refer to <ulink url="https://www.torproject.org/documentation.html">Tor's
1826 extensive documentation</ulink> to learn how to install <application>Tor</application>,
1827 and make sure <application>Tor</application>'s logfile says that
1828 <quote>Tor has successfully opened a circuit</quote> and it
1829 <quote>looks like client functionality is working</quote>.
1832 If either <application>Tor</application> or <application>Privoxy</application>
1833 isn't working, their combination most likely will neither. Testing them on their
1834 own will also help you to direct problem reports to the right audience.
1835 If <application>Privoxy</application> isn't working, don't bother the
1836 <application>Tor</application> developers. If <application>Tor</application>
1837 isn't working, don't send bug reports to the <application>Privoxy</application> Team.
1840 If you verified that <application>Privoxy</application> and <application>Tor</application>
1841 are working, it is time to connect them. As far as <application>Privoxy</application>
1842 is concerned, <application>Tor</application> is just another proxy that can be reached
1843 by socks4, socks4a and socks5. Most likely you are interested in <application>Tor</application>
1844 to increase your anonymity level, therefore you should use socks5, to make sure DNS
1845 requests are done through <application>Tor</application> and thus invisible to your
1846 local network. Using socks4a would work too, but with socks5 you get more precise error
1851 <application>Privoxy's</application>
1852 <ulink url="../user-manual/config.html">main configuration file</ulink>
1853 is already prepared for <application>Tor</application>, if you are using a
1854 default <application>Tor</application> configuration and run it on the same
1855 system as &my-app;, you just have to edit the
1856 <ulink url="../user-manual/config.html#FORWARDING">forwarding section</ulink>
1857 and uncomment the line:
1861 # forward-socks5t / 127.0.0.1:9050 .
1865 Note that if you got Tor through one of the bundles, you may
1866 have to change the port from 9050 to 9150 (or even another one).
1867 For details, please check the documentation on the
1868 <ulink url="https://torproject.org/">Tor website</ulink>.
1872 This is enough to reach the Internet, but additionally you might want to
1873 uncomment the following forward rules, to make sure your local network is still
1874 reachable through Privoxy:
1878 # forward 192.168.*.*/ .
1879 # forward 10.*.*.*/ .
1880 # forward 127.*.*.*/ .
1884 Unencrypted connections to systems in these address ranges will
1885 be as (un)secure as the local network is, but the alternative is
1886 that your browser can't reach the network at all. Then again,
1887 that may actually be desired and if you don't know for sure
1888 that your browser has to be able to reach the local network,
1889 there's no reason to allow it.
1892 If you want your browser to be able to reach servers in your local
1893 network by using their names, you will need additional exceptions
1894 that look like this:
1898 # forward localhost/ .
1902 Save the modified configuration file and open
1903 <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1904 in your browser, confirm that <application>Privoxy</application> has reloaded its configuration
1905 and that there are no other forward lines, unless you know that you need them. If everything looks good,
1907 <ulink url="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#IsMyConnectionPrivate">Tor
1908 Faq 4.2</ulink> to learn how to verify that you are really using <application>Tor</application>.
1911 Afterward, please take the time to at least skim through the rest
1912 of <application>Tor's</application> documentation. Make sure you understand
1913 what <application>Tor</application> does, why it is no replacement for
1914 application level security, and why you probably don't want to
1915 use it for unencrypted logins.
1919 <sect2 renderas="sect3" id="sitebreak">
1920 <title>Might some things break because header information or
1921 content is being altered?</title>
1924 Definitely. It is common for sites to use browser type, browser version,
1925 HTTP header content, and various other techniques in order to dynamically
1926 decide what to display and how to display it. What you see, and what I see,
1927 might be very different. There are many, many ways that this can be handled,
1928 so having hard and fast rules, is tricky.
1932 The <quote>User-Agent</quote> is sometimes used in this way to identify
1933 the browser, and adjust content accordingly.
1937 Also, different browsers use different encodings of non-English
1938 characters, certain web servers convert pages on-the-fly according to the
1939 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1940 operating system or browser manufacturer causes some sites in these languages
1941 to be garbled; Surfers to Eastern European sites should change it to
1942 something closer. And then some page access counters work by looking at the
1943 <quote>Referer</quote> header; they may fail or break if unavailable. The
1944 weather maps of Intellicast have been blocked by their server when no
1945 <quote>Referer</quote> or cookie is provided, is another example. (But you
1946 can forge both headers without giving information away). There are
1947 many other ways things can go wrong when trying to fool a web server. The
1948 results of which could inadvertently cause pages to load incorrectly,
1949 partially, or even not at all. And there may be no obvious clues as to just
1950 what went wrong, or why. Nowhere will there be a message that says
1951 <quote><emphasis>Turn off <literal>fast-redirects</literal> or else!</emphasis>
1956 Similar thoughts apply to modifying JavaScript, and, to a lesser degree,
1961 If you have problems with a site, you will have to adjust your configuration
1962 accordingly. Cookies are probably the most likely adjustment that may
1963 be required, but by no means the only one.
1969 <sect2 renderas="sect3" id="caching">
1970 <title>Can Privoxy act as a <quote>caching</quote> proxy to
1971 speed up web browsing?</title>
1973 No, it does not have this ability at all. You want something like
1974 <ulink url="http://www.squid-cache.org/">Squid</ulink> or
1975 <ulink url="http://www.pps.jussieu.fr/~jch/software/polipo/">Polipo</ulink> for this.
1976 And, yes, before you ask, <application>Privoxy</application> can co-exist
1977 with other kinds of proxies like <application>Squid</application>.
1978 See the <ulink url="../user-manual/config.html#FORWARDING">forwarding
1979 chapter</ulink> in the <ulink url="../user-manual/index.html">user
1980 manual</ulink> for details.
1984 <sect2 renderas="sect3" id="firewall">
1985 <title>What about as a firewall? Can Privoxy protect me?</title>
1987 Not in the way you mean, or in the way some firewall vendors claim they can.
1988 <application>Privoxy</application> can help protect your privacy, but can't
1989 protect your system from intrusion attempts. It is, of course, perfectly possible
1990 to use <emphasis>both</emphasis>.
1994 <sect2 renderas="sect3" id="wasted">
1995 <title>I have large empty spaces / a checkerboard pattern now where
1996 ads used to be. Why?</title>
1998 It is technically possible to eliminate banners and ads in a way that frees
1999 their allocated page space. This could easily be done by blocking with
2000 <application>Privoxy's</application> filters,
2001 and eliminating the <emphasis>entire</emphasis> image references from the
2005 But, this would consume considerably more CPU resources (IOW, slow things
2006 down), would likely destroy the layout of some web pages which rely on the
2007 banners utilizing a certain amount of page space, and might fail in other
2008 cases, where the screen space is reserved (e.g. by HTML tables for instance).
2009 Also, making ads and banners disappear without any trace complicates
2010 troubleshooting, and would sooner or later be problematic.
2013 The better alternative is to instead let them stay, and block the resulting
2014 requests for the banners themselves as is now the case. This leaves either
2015 empty space, or the familiar checkerboard pattern.
2018 So the developers won't support this in the default configuration, but you
2019 can of course define appropriate filters yourself to achieve this.
2023 <sect2 renderas="sect3" id="ssl">
2024 <title>How can Privoxy filter Secure (HTTPS) URLs?</title>
2026 Since secure HTTP connections are encrypted SSL sessions between your browser
2027 and the secure site, and are meant to be reliably <emphasis>secure</emphasis>,
2028 there is little that <application>Privoxy</application> can do but hand the raw
2029 gibberish data though from one end to the other unprocessed.
2032 The only exception to this is blocking by host patterns, as the client needs
2033 to tell <application>Privoxy</application> the name of the remote server,
2034 so that <application>Privoxy</application> can establish the connection.
2035 If that name matches a host-only pattern, the connection will be blocked.
2038 As far as ad blocking is concerned, this is less of a restriction than it may
2039 seem, since ad sources are often identifiable by the host name, and often
2040 the banners to be placed in an encrypted page come unencrypted nonetheless
2041 for efficiency reasons, which exposes them to the full power of
2042 <application>Privoxy</application>'s ad blocking.
2045 <quote>Content cookies</quote> (those that are embedded in the actual HTML or
2046 JS page content, see <literal><ulink
2047 url="../user-manual/actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</ulink></literal>),
2048 in an SSL transaction will be impossible to block under these conditions.
2049 Fortunately, this does not seem to be a very common scenario since most
2050 cookies come by traditional means.
2055 <sect2 renderas="sect3" id="secure">
2056 <title>Privoxy runs as a <quote>server</quote>. How
2057 secure is it? Do I need to take any special precautions?</title>
2059 On Unix-like systems, <application>Privoxy</application> can run as a non-privileged
2060 user, which is how we recommend it be run. Also, by default
2061 <application>Privoxy</application> listens to requests from <quote>localhost</quote>
2065 The server aspect of <application>Privoxy</application> is not itself directly
2066 exposed to the Internet in this configuration. If you want to have
2067 <application>Privoxy</application> serve as a LAN proxy, this will have to
2068 be opened up to allow for LAN requests. In this case, we'd recommend
2069 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
2070 <application>Privoxy</application> configuration file and check all <ulink
2071 url="../user-manual/config.html#ACCESS-CONTROL">access control and security
2072 options</ulink>. All LAN hosts can then use this as their proxy address
2073 in the browser proxy configuration, but <application>Privoxy</application>
2074 will not listen on any external interfaces. ACLs can be defined in addition,
2075 and using a firewall is always good too. Better safe than sorry.
2080 <sect2 renderas="sect3" id="turnoff">
2081 <title>Can I temporarily disable Privoxy?</title>
2083 &my-app; doesn't have a transparent proxy mode,
2084 but you can toggle off blocking and content filtering.
2087 The easiest way to do that is to point your browser
2088 to the remote toggle URL: <ulink
2089 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>.
2092 See the <ulink url="../user-manual/appendix.html#BOOKMARKLETS">Bookmarklets section</ulink>
2093 of the <citetitle>User Manual</citetitle> for an easy way to access this
2094 feature. Note that this is a feature that may need to be enabled in the main
2095 <filename>config</filename> file.
2100 <sect2 renderas="sect3" id="reallyoff">
2101 <title>When <quote>disabled</quote> is Privoxy totally
2102 out of the picture?</title>
2104 No, this just means all optional filtering and actions are disabled.
2105 <application>Privoxy</application> is still acting as a proxy, but just
2106 doing less of the things that <application>Privoxy</application> would
2107 normally be expected to do. It is still a <quote>middle-man</quote> in
2108 the interaction between your browser and web sites. See below to bypass
2113 <sect2 renderas="sect3" id="turnoff2">
2114 <title>How can I tell Privoxy to totally ignore certain sites?</title>
2116 Bypassing a proxy, or proxying based on arbitrary criteria, is purely a browser
2117 configuration issue, not a &my-app; issue. Modern browsers typically do have
2118 settings for not proxying certain sites. Check your browser's help files.
2123 <sect2 renderas="sect3" id="crunch">
2124 <title>My logs show Privoxy <quote>crunches</quote>
2125 ads, but also its own internal CGI pages. What is a <quote>crunch</quote>?</title>
2127 A <quote>crunch</quote> simply means <application>Privoxy</application> intercepted
2128 <emphasis>something</emphasis>, nothing more. Often this is indeed ads or
2129 banners, but <application>Privoxy</application> uses the same mechanism for
2130 trapping requests for its own internal pages. For instance, a request for
2131 <application>Privoxy's</application> configuration page at: <ulink
2132 url="http://config.privoxy.org">http://config.privoxy.org</ulink>, is
2133 intercepted (i.e. it does not go out to the 'net), and the familiar CGI
2134 configuration is returned to the browser, and the log consequently will show
2135 a <quote>crunch</quote>.
2138 Since version 3.0.7, Privoxy will also log the crunch reason.
2139 If you are using an older version you might want to upgrade.
2143 <sect2 renderas="sect3" id="downloads">
2144 <title>Can Privoxy affect files that I download
2145 from a webserver? FTP server?</title>
2147 From the webserver's perspective, there is no difference between
2148 viewing a document (i.e. a page), and downloading a file. The same is true of
2149 <application>Privoxy</application>. If there is a match for a <literal><ulink
2150 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> pattern,
2151 it will still be blocked, and of course this is obvious.
2154 Filtering is potentially more of a concern since the results are not always
2155 so obvious, and the effects of filtering are there whether the file is simply
2156 viewed, or downloaded. And potentially whether the content is some obnoxious
2157 advertisement, or Mr. Jimmy's latest/greatest source code jewel. Of course,
2158 one of these presumably is <quote>bad</quote> content that we don't want, and
2159 the other is <quote>good</quote> content that we do want.
2160 <application>Privoxy</application> is blind to the differences, and can only
2161 distinguish <quote>good from bad</quote> by the configuration parameters
2162 <emphasis>we</emphasis> give it.
2165 <application>Privoxy</application> knows the differences in files according
2166 to the <quote>Content Type</quote> as reported by the webserver. If this is
2167 reported accurately (e.g. <quote>application/zip</quote> for a zip archive),
2168 then <application>Privoxy</application> knows to ignore these where
2169 appropriate. <application>Privoxy</application> potentially can filter HTML
2170 as well as plain text documents, subject to configuration parameters of
2171 course. Also, documents that are of an unknown type (generally assumed to be
2172 <quote>text/plain</quote>) can be filtered, as will those that might be
2173 incorrectly reported by the webserver. If such a file is a downloaded file
2174 that is intended to be saved to disk, then any content that might have been
2175 altered by filtering, will be saved too, for these (probably rare) cases.
2178 Note that versions later than 3.0.2 do NOT filter document types reported as
2179 <quote>text/plain</quote>. Prior to this, <application>Privoxy</application>
2180 did filter this document type.
2183 In short, filtering is <quote>ON</quote> if a) the content type as reported
2184 by the webserver is appropriate <emphasis>and</emphasis> b) the configuration
2185 allows it (or at least does not disallow it). That's it. There is no magic
2186 cookie anywhere to say this is <quote>good</quote> and this is
2187 <quote>bad</quote>. It's the configuration that lets it all happen or not.
2190 If you download text files, you probably do not want these to be filtered,
2191 particularly if the content is source code, or other critical content. Source
2192 code sometimes might be mistaken for Javascript (i.e. the kind that might
2193 open a pop-up window). It is recommended to turn off filtering for download
2194 sites (particularly if the content may be plain text files and you are using
2195 version 3.0.2 or earlier) in your <filename>user.action</filename> file. And
2196 also, for any site or page where making <emphasis>any</emphasis> changes at
2197 all to the content is to be avoided.
2200 <application>Privoxy</application> does not do FTP at all, only HTTP
2201 and HTTPS (SSL) protocols.
2205 <sect2 renderas="sect3" id="downloads2">
2206 <title>I just downloaded a Perl script, and Privoxy
2207 altered it! Yikes, what is wrong!</title>
2213 <sect2 renderas="sect3" id="hostsfile">
2214 <title>Should I continue to use a <quote>HOSTS</quote> file for ad-blocking?</title>
2216 One time-tested technique to defeat common ads is to trick the local DNS
2217 system by giving a phony IP address for the ad generator in the local
2218 <filename>HOSTS</filename> file, typically using <literal>127.0.0.1</literal>, aka
2219 <literal>localhost</literal>. This effectively blocks the ad.
2222 There is no reason to use this technique in conjunction with
2223 <application>Privoxy</application>. <application>Privoxy</application>
2224 does essentially the same thing, much more elegantly and with much more
2225 flexibility. A large <filename>HOSTS</filename> file, in fact, not only
2226 duplicates effort, but may get in the way and seriously slow down your system.
2227 It is recommended to remove such entries from your <filename>HOSTS</filename> file. If you think
2228 your hosts list is neglected by <application>Privoxy's </application>
2229 configuration, consider adding your list to your <filename>user.action</filename> file:
2236 ads.galore.example.com
2237 etc.example.com</screen>
2241 <sect2 renderas="sect3" id="seealso">
2242 <title>Where can I find more information about Privoxy
2243 and related issues?</title>
2244 <!-- Include seealso.sgml boilerplate: -->
2246 <!-- end boilerplate -->
2251 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
2257 <sect2 renderas="sect3" id="microsuck">
2258 <title>I've noticed that Privoxy changes <quote>Microsoft</quote> to
2259 <quote>MicroSuck</quote>! Why are you manipulating my browsing?</title>
2262 We're not. The text substitutions that you are seeing are disabled
2263 in the default configuration as shipped. You have either manually
2264 activated the <quote><literal>fun</literal></quote> filter which
2265 is clearly labeled <quote>Text replacements for subversive browsing
2266 fun!</quote> or you are using an older Privoxy version and have implicitly
2267 activated it by choosing the <quote>Advanced</quote> profile in the
2268 web-based editor. Please upgrade.
2272 <sect2 renderas="sect3" id="valid">
2273 <title>Does Privoxy produce <quote>valid</quote> HTML (or XHTML)?</title>
2276 Privoxy generates HTML in both its own <quote>templates</quote>, and possibly
2277 whenever there are text substitutions via a &my-app; filter. While this
2278 should always conform to the HTML 4.01 specifications, it has not been
2279 validated against this or any other standard.
2283 <sect2 renderas="sect3" id="surprise-privoxy">
2284 <title>How did you manage to get Privoxy on my computer without my consent?</title>
2287 We didn't. We make Privoxy available for download, but we don't go
2288 around installing it on other people's systems behind their back.
2289 If you discover Privoxy running on your system and are sure you didn't
2290 install it yourself, somebody else did. You may not even be running
2291 the real Privoxy, but maybe something else that only pretends to be
2292 Privoxy, or maybe something that is based on the real Privoxy,
2293 but has been modified.
2296 Lately there have been reports of problems with some kind of
2297 "parental control" software based on Privoxy that came preinstalled on
2298 certain <ulink url="https://sourceforge.net/p/ijbswa/bugs/813/">ASUS Netbooks</ulink>.
2299 The problems described are inconsistent with the behaviour of official
2300 Privoxy versions, which suggests that the preinstalled software may
2301 contain vendor modifications that we don't know about and thus can't debug.
2304 Privoxy's <link linkend="copyright">license</link> allows vendor
2305 modifications, but the vendor has to comply with the license,
2306 which involves informing the user about the changes and to make
2307 the changes available under the same license as Privoxy itself.
2310 If you are having trouble with a modified Privoxy version,
2311 please try to talk to whoever made the modifications before
2312 reporting the problem to us. Please also try to convince
2313 whoever made the modifications to talk to us. If you think
2314 somebody gave you a modified Privoxy version without complying
2315 to the license, please let us know.
2323 <!-- ~~~~~ New section ~~~~~ -->
2325 <sect1 id="trouble">
2326 <title>Troubleshooting</title>
2328 <sect2 renderas="sect3" id="refused">
2329 <title>I cannot connect to any websites. Or, I am getting
2330 <quote>connection refused</quote> message with every web page. Why?</title>
2332 There are several possibilities:
2337 <application>Privoxy</application> is not running. Solution: verify
2338 that &my-app; is installed correctly, has not crashed, and is indeed running.
2339 Turn on <application>Privoxy's</application> logging, and look at the logs to see what they say.
2341 <listitem><para>Or your browser is configured for a different port than what
2342 <application>Privoxy</application> is using. Solution: verify that &my-app;
2343 and your browser are set to the same port (<literal>listen-address</literal>).
2345 <listitem><para>Or if using a forwarding rule, you have a configuration problem or a
2346 problem with a host in the forwarding chain. Solution: temporarily alter your
2347 configuration and take the forwarders out of the equation.
2350 Or you have a firewall that is interfering and blocking you. Solution:
2351 try disabling or removing the firewall as a simple test.
2358 <!-- ~~~~~ New section ~~~~~ -->
2359 <sect2 renderas="sect3" id="error503">
2360 <title>Why am I getting a 503 Error (WSAECONNREFUSED) on every page?</title>
2362 More than likely this is a problem with your TCP/IP networking. ZoneAlarm has
2363 been reported to cause this symptom -- even if not running! The solution is
2364 to either fight the ZA configuration, or uninstall ZoneAlarm, and then find
2365 something better behaved in its place. Other personal firewall type products
2366 may cause similar type problems if not configured correctly.
2370 <sect2 renderas="sect3" id="flushit">
2371 <title>I just added a new rule, but the steenkin ad is
2372 still getting through. How?</title>
2374 If the ad had been displayed before you added its URL, it will probably be
2375 held in the browser's cache for some time, so it will be displayed without
2376 the need for any request to the server, and <application>Privoxy</application>
2377 will not be involved. Flush the browser's caches, and then try again.
2381 If this doesn't help, you probably have an error in the rule you
2382 applied. Try pasting the full URL of the offending ad into <ulink
2383 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2384 and see if it really matches your new rule. Blocking ads is like blocking
2385 spam: a lot of tinkering is required to stay ahead of the game. And
2386 remember you need to block the URL of the ad in question, which may be
2387 entirely different from the site URL itself. Most ads are hosted on different
2388 servers than the main site itself. If you right-click on the ad, you should
2389 be able to get all the relevant information you need. Alternately, you can
2390 find the correct URL by looking at <application>Privoxy's</application> logs
2391 (you may need to enable logging in the main config file if its disabled).
2394 Below is a slightly modified real-life log snippet that originates with one
2395 requested URL: <literal>www.example.com</literal> (name of site was changed
2396 for this example, the number of requests is real). You can see in this the
2397 complexity of what goes into making up this one <quote>page</quote>. There
2398 are eight different domains involved here, with thirty two separate URLs
2399 requested in all, making up all manner of images, Shockwave Flash,
2400 JavaScript, CSS stylesheets, scripts, and other related content. Some of this
2401 content is obviously <quote>good</quote> or <quote>bad</quote>, but not all.
2402 Many of the more questionable looking requests, are going to outside domains
2403 that seem to be identifying themselves with suspicious looking names, making
2404 our job a little easier. &my-app; has <quote>crunched</quote> (meaning caught
2405 and BLOCKED) quite a few items in this example, but perhaps missed a few as well.
2410 Request: www.example.com/
2411 Request: www.example.com/favicon.ico
2412 Request: img.example.com/main.css
2413 Request: img.example.com/sr.js
2414 Request: example.betamarker.com/example.html
2415 Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
2416 Request: img.example.com/pb.png
2417 Request: www.google-analytics.com/urchin.js crunch! (Blocked)
2418 Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch! (Blocked)
2419 Request: img.example.com/p.gif
2420 Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch! (Blocked)
2421 Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch! (Blocked)
2422 Request: www.popuptraffic.com/assign.php?l=example crunch! (Blocked)
2423 Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
2424 Request: www.adtrak.net/adx.js crunch! (Blocked)
2425 Request: img.example.com/hbg.gif
2426 Request: img.example.com/example.jpg
2427 Request: img.example.com/mt.png
2428 Request: img.example.com/mm.png
2429 Request: img.example.com/mb.png
2430 Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch! (Blocked)
2431 Request: www.example.com/tracker.js
2432 Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
2433 Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch! (Blocked)
2434 Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch! (Blocked)
2435 Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
2436 Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch! (Blocked)
2437 Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
2438 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch! (Blocked)
2439 Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
2440 Request: 66.70.21.80/img/pixel.gif
2441 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch! (Blocked)
2442 Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
2447 Despite 12 out of 32 requests being blocked, the page looked, and seemed to
2448 behave perfectly <quote>normal</quote> (minus some ads, of course).
2453 <sect2 renderas="sect3" id="badsite">
2454 <title>One of my favorite sites does not work with Privoxy.
2455 What can I do?</title>
2458 First verify that it is indeed a <application>Privoxy</application> problem,
2459 by toggling off <application>Privoxy</application> through <ulink
2460 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
2461 (the toggle feature may need to be enabled in the main
2462 <filename>config</filename>),
2463 and then shift-reloading the problem page (i.e. holding down the shift key
2464 while clicking reload. Alternatively, flush your browser's disk and memory
2469 If the problem went away, we know we have a configuration related problem.
2471 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2472 and paste the full URL of the page in question into the prompt. See which
2473 actions are being applied to the URL, and which matches in which actions
2474 files are responsible for that. It might be helpful also to look at your logs
2475 for this site too, to see what else might be happening (note: logging may need
2476 to be enabled in the main config file). Many sites are
2477 complex and require a number of related pages to help present their content.
2478 Look at what else might be used by the page in question, and what of that
2479 might be <emphasis>required</emphasis>.
2480 Now, armed with this information, go to
2482 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2483 and select the appropriate actions files for editing. </para>
2485 You can now either look for a section which disables the actions that
2486 you suspect to cause the problem and add a pattern for your site there,
2487 or make up a completely new section for your site. In any case, the recommended
2488 way is to disable only the prime suspect, reload the problem page, and only
2489 if the problem persists, disable more and more actions until you have
2490 identified the culprit. You may or may not want to turn the other actions
2491 on again. Remember to flush your browser's caches in between any such changes!
2494 Alternately, if you are comfortable with a text editor, you can accomplish
2495 the same thing by editing the appropriate actions file. Probably the easiest
2496 way to deal with such problems when editing by hand is to add your
2497 site to a <literal>{ fragile }</literal> section in <filename>user.action</filename>,
2498 which is an alias that turns off most <quote>dangerous</quote>
2499 actions, but is also likely to turn off more actions then needed, and thus lower
2500 your privacy and protection more than necessary,
2503 Troubleshooting actions is discussed in more detail in the <ulink
2504 url="../user-manual/appendix.html#ACTIONSANAT">User Manual appendix,
2505 Troubleshooting: the Anatomy of an Action</ulink>.
2506 There is also an <ulink
2507 url="../user-manual/actions-file.html#ACT-EXAMPLES">actions tutorial</ulink>
2508 with general configuration information and examples.
2511 As a last resort, you can always see if your browser has a setting that will
2512 bypass the proxy setting for selective sites. Modern browsers can do this.
2518 <!-- ~~~~~ New section ~~~~~ -->
2519 <sect2 id="dun" renderas="sect3">
2520 <title>After installing Privoxy, I have to log in
2521 every time I start IE. What gives?</title>
2524 This is a quirk that affects the installation of
2525 <application>Privoxy</application>, in conjunction with Internet Explorer and
2526 Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may
2527 appear to be corrupted or invalid DUN settings, or passwords.
2531 When setting up an NT based Windows system with
2532 <application>Privoxy</application> you may find that things do not seem to be
2533 doing what you expect. When you set your system up you will probably have set
2534 up Internet Connection Sharing (ICS) with Dial up Networking (DUN) when
2535 logged in with administrator privileges. You will probably have made this DUN
2536 connection available to other accounts that you may have set-up on your
2537 system. E.g. Mum or Dad sets up the system and makes accounts suitably
2538 configured for the kids.
2542 When setting up <application>Privoxy</application> in this environment you
2543 will have to alter the proxy set-up of Internet Explorer (IE) for the
2544 specific DUN connection on which you wish to use
2545 <application>Privoxy</application>. When you do this the ICS DUN set-up
2546 becomes user specific. In this instance you will see no difference if you
2547 change the DUN connection under the account used to set-up the connection.
2548 However when you do this from another user you will notice that the DUN
2549 connection changes to make available to "Me only". You will also find that
2550 you have to store the password under each different user!
2554 The reason for this is that each user's set-up for IE is user specific. Each
2555 set-up DUN connection and each LAN connection in IE store the settings for
2556 each user individually. As such this enforces individual configurations
2557 rather than common ones. Hence the first time you use a DUN connection after
2558 re-booting your system it may not perform as you expect, and prompt you for
2559 the password. Just set and save the password again and all should be OK.
2563 [Thanks to Ray Griffith for this submission.]
2568 <!-- ~~~~~ New section ~~~~~ -->
2569 <sect2 id="ftp" renderas="sect3">
2570 <title>I cannot connect to any FTP sites. Privoxy
2571 is blocking me.</title>
2573 <application>Privoxy</application> cannot act as a proxy for FTP traffic,
2574 so do not configure your browser to use <application>Privoxy</application>
2575 as an FTP proxy. The same is true for <emphasis>any protocol other than HTTP
2576 or HTTPS (SSL)</emphasis>.
2579 Most browsers understand FTP as well as HTTP. If you connect to a site, with
2580 a URL like <literal>ftp://ftp.example.com</literal>, your browser is making
2581 an FTP connection, and not a HTTP connection. So while your browser may
2582 speak FTP, <application>Privoxy</application> does not, and cannot proxy
2586 To complicate matters, some systems may have a generic <quote>proxy</quote>
2587 setting, which will enable various protocols, including
2588 <emphasis>both</emphasis> HTTP and FTP proxying! So it is possible to
2589 accidentally enable FTP proxying in these cases. And of course, if this
2590 happens, <application>Privoxy</application> will indeed cause problems since
2591 it does not know FTP. <![%p-newstuff;[Newer version will give a sane error
2592 message if a FTP connection is attempted.]]> Just disable the FTP setting
2593 and all will be well again.
2596 Will <application>Privoxy</application> ever proxy FTP traffic? Unlikely.
2597 There just is not much reason, and the work to make this happen is more than
2602 <!-- ~~~~~ New section ~~~~~ -->
2603 <sect2 id="macosxie" renderas="sect3">
2604 <title>In Mac OS X, I can't configure Microsoft Internet Explorer to use
2605 Privoxy as the HTTP proxy.</title>
2607 Microsoft Internet Explorer (in versions like 5.1) respects system-wide
2608 network settings. In order to change the HTTP proxy, open System
2609 Preferences, and click on the Network icon. In the settings pane that
2610 comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox
2611 is checked and enter <literal>127.0.0.1</literal> in the entry field.
2612 Enter <literal>8118</literal> in the Port field. The next time you start
2613 IE, it should reflect these values.
2617 <!-- ~~~~~ New section ~~~~~ -->
2618 <sect2 renderas="sect3" id="macosxuninstall">
2619 <title>In Mac OS X, I dragged the Privoxy folder to the trash in order to
2620 uninstall it. Now the finder tells me I don't have sufficient privileges to
2621 empty the trash.</title>
2623 Note: This ONLY applies to privoxy 3.0.6 and earlier.
2626 Just dragging the <application>Privoxy</application> folder to the trash is
2627 not enough to delete it. <application>Privoxy</application> supplies an
2628 <application>uninstall.command</application> file that takes care of
2629 these details. Open the trash, drag the <application>uninstall.command</application>
2630 file out of the trash and double-click on it. You will be prompted for
2631 confirmation and the administration password.
2634 The trash may still appear full after this command; emptying the trash
2635 from the desktop should make it appear empty again.
2639 <!-- ~~~~~ New section ~~~~~ -->
2640 <sect2 renderas="sect3" id="macosximages">
2641 <title>In Mac OS X Panther (10.3), images often fail to load and/or I
2642 experience random delays in page loading. I'm using
2643 <literal>localhost</literal> as my browser's proxy setting.</title>
2645 We believe this is due to an IPv6-related bug in Mac OS X, but don't fully
2646 understand the issue yet. In any case, changing the proxy setting to
2647 <literal>127.0.0.1</literal> instead of <literal>localhost</literal>
2648 works around the problem.
2652 <!-- ~~~~~ New section ~~~~~ -->
2653 <sect2 renderas="sect3" id="macosxaccountdeletion">
2654 <title>I just upgraded to Mac OS X 10.9 (Mavericks) and now &my-app; has stopped
2657 The upgrade process to Mac OS X Mavericks (10.9) from an earlier version of OS
2658 X deletes all user accounts that are either not part of OS X itself or are
2659 not interactive user accounts (ones you log in with). Since, for the sake of
2660 security, &my-app; runs as a non-privileged user that is created by its
2661 installer (_privoxy), it can no longer start up once that account gets deleted.
2662 The solution is to perform a complete uninstall using the supplied
2663 <application>uninstall.command</application> script (either back up your
2664 configuration files or select to not have the uninstaller remove them when it
2665 prompts you) and then reinstall &my-app; using the installer package and merge
2666 in your configuration.
2670 <sect2 renderas="sect3" id="nohostname">
2671 <title>My logs show many <quote>Unable to get my own hostname</quote> lines.
2674 <application>Privoxy</application> tries to get the hostname of the system
2675 its running on from the IP address of the system interface it is bound to
2676 (from the <filename>config</filename> file
2677 <emphasis>listen-address</emphasis> setting). If the system cannot supply
2678 this information, <application>Privoxy</application> logs this condition.
2681 Typically, this would be considered a minor system configuration error. It is
2682 not a fatal error to <application>Privoxy</application> however, but may
2683 result in a much slower response from <application>Privoxy</application> on
2684 some platforms due to DNS timeouts.
2687 This can be caused by a problem with the local <filename>hosts</filename>
2688 file. If this file has been changed from the original, try reverting it to
2689 see if that helps. Make sure whatever name(s) are used for the local system,
2690 that they resolve both ways.
2693 You should also be able to work around the problem with the
2694 <ulink url="../user-manual/config.html#HOSTNAME">hostname option</ulink>.
2698 <sect2 renderas="sect3" id="inuse">
2699 <title>When I try to launch Privoxy, I get an
2700 error message <quote>port 8118 is already in use</quote> (or similar wording).
2703 Port 8118 is <application>Privoxy's</application> default TCP
2704 <quote>listening</quote> port. Typically this message would mean that there
2705 is already one instance of <application>Privoxy</application> running, and
2706 your system is actually trying to start a second
2707 <application>Privoxy</application> on the same port, which will not work.
2708 (You can have multiple instances but they must be assigned different ports.)
2709 How and why this might happen varies from platform to platform, but you need
2710 to check your installation and start-up procedures.
2714 <sect2 renderas="sect3" id="demoronizer">
2716 Pages with UTF-8 fonts are garbled.
2719 This may be the result of an overly aggressive filter. The filters that
2720 are enabled in the default configuration aren't expected to cause problems
2721 like this. If you enabled the <quote>demoronizer</quote> filter, please
2722 try temporarily disabling it.
2725 If that doesn't help, temporarily disable all filters to see if another
2726 filter could be the culprit. If the problem disappears, enable the filters
2727 one by one, until the problem reappears and the offending filter is found.
2730 Once the problem-causing filter is known, it can be fixed or disabled.
2733 Upgrading <application>Privoxy</application>, or going to the most recent
2734 <filename>default.action</filename> file available from <ulink
2735 url="https://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>
2736 might be worth a try, too.
2740 <sect2 renderas="sect3" id="demoronizer2">
2742 Why are binary files (such as images) corrupted when Privoxy
2746 This may also be caused by an (<link linkend="DEMORONIZER">overly aggressive
2747 filter</link> in conjunction with a web server that is misreporting the content
2748 type. By default binary files are exempted from
2749 <application>Privoxy's</application> filtering
2750 (unless the web server by mistake says the file is something else).
2754 <sect2 renderas="sect3" id="demoronizer3">
2756 What is the <quote>demoronizer</quote> and why is it there?
2759 The original demoronizer was a Perl script that cleaned up HTML pages which
2760 were created with certain Microsoft products. MS has used proprietary extensions
2761 to standardized font encodings (ISO 8859-1), which has caused problems for pages
2762 that are viewed with non-Microsoft products (and are expecting to see a
2763 standard set of fonts). The demoronizer corrected these errors so the pages
2764 displayed correctly. <application>Privoxy</application> borrowed from this
2765 script, introducing a filter based on the original demoronizer, which in turn could
2766 correct these errors on the fly.
2769 But this is only needed in some situations, and will cause serious problems in some
2773 If you are using Microsoft products, you do not need it. If you need to view
2774 pages with UTF-8 characters (such as Cyrillic or Chinese), then it will
2775 cause corruption of the fonts, and thus <emphasis>should not be on</emphasis>.
2778 On the other hand, if you use non-Microsoft products, and you occasionally
2779 notice weird characters on pages, you might want to try it.
2783 <sect2 renderas="sect3" id="windowopen">
2785 Why do I keep seeing <quote>PrivoxyWindowOpen()</quote> in raw source code?
2788 <application>Privoxy</application> is attempting to disable malicious
2789 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink>
2790 in this case, with the <literal>unsolicited-popups</literal>
2791 filter. <application>Privoxy</application> cannot tell very well
2792 <quote>good</quote> code snippets from <quote>bad</quote> code snippets.
2795 If you see this in HTML source, and the page displays without problems, then
2796 this is good, and likely some pop-up window was disabled. If you see this
2797 where it is causing a problem, such as a downloaded program source code file,
2798 then you should set an exception for this site or page such that the
2799 integrity of the page stays in tact by disabling all filtering.
2803 <sect2 renderas="sect3" id="dnserrors">
2805 I am getting too many DNS errors like <quote>404 No Such Domain</quote>. Why
2806 can't Privoxy do this better?
2809 There are potentially several factors here. First of all, the DNS resolution
2810 is done by the underlying operating system -- not
2811 <application>Privoxy</application> itself. <application>Privoxy</application>
2812 merely initiates the process and hands it off, and then later reports
2813 whatever the outcome was and tries to give a coherent message if there seems
2814 to be a problem. In some cases, this might otherwise be mitigated by the
2815 browser itself which might try some work-arounds and alternate approaches (e.g
2816 adding <quote>www.</quote> to the URL).
2819 In other cases, if <application>Privoxy</application> is being chained
2820 with another proxy, this could complicate the issue, and cause undue
2821 delays and timeouts. In the case of a <quote>socks4a</quote> proxy, the socks
2822 server handles all the DNS. <application>Privoxy</application> would just be
2823 the <quote>messenger</quote> which is reporting whatever problem occurred
2824 downstream, and not the root cause of the error.
2828 In any case, versions newer than 3.0.3 include various improvements to help
2829 <application>Privoxy</application> better handle these cases.
2833 <sect2 renderas="sect3" id="allcpu">
2835 At one site Privoxy just hangs, and starts taking
2836 all CPU. Why is this?
2839 This is probably a manifestation of the <quote>100% cpu</quote> problem that
2840 occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines
2841 are in the raw HTML source of the page, and the browser just ignores them. But the
2842 pattern matching in <application>Privoxy's</application> page filtering
2843 mechanism is trying to match against absurdly long strings and this becomes
2844 very CPU-intensive, taking a long, long time to complete.
2847 Until a better solution comes along, disable filtering on these pages,
2848 particularly the <literal>js-annoyances</literal> and
2849 <literal>unsolicited-popups</literal> filters. If you run into this problem
2850 with a recent &my-app; version, please send a problem report.
2854 <sect2 renderas="sect3" id="slowcrawl">
2855 <title>I just installed Privoxy, and all my
2856 browsing has slowed to a crawl. What gives? </title>
2858 This should not happen, and for the overwhelming number of users world-wide,
2859 it does not happen. I would suspect some inadvertent interaction of software
2860 components such as anti-virus software, spyware protectors, personal
2861 firewalls or similar components. Try disabling (or uninstalling) these one
2862 at a time and see if that helps. Either way, if you are using a
2863 recent &my-app; version, please report the problem.
2867 <sect2 renderas="sect3" id="preventcomp">
2868 <title>Why do my filters work on some sites but not on others? </title>
2870 It's probably due to compression. It is a common practice for web servers to
2871 send their content <quote>compressed</quote> in order to speed things up, and
2872 then let the browser <quote>uncompress</quote> them. When compiled with zlib support
2873 &my-app; can decompress content before filtering, otherwise you may want to enable
2875 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>.
2878 As of &my-app; 3.0.9, zlib support is enabled in the default builds.
2883 <sect2 renderas="sect3" id="ssl-warnings">
2884 <title>On some HTTPS sites my browser warns me about unauthenticated content,
2885 the URL bar doesn't get highlighted and the lock symbol appears to be broken.
2886 What's going on?</title>
2888 Probably the browser is requesting ads through HTTPS and &my-app;
2889 is blocking the requests. Privoxy's error messages are delivered
2890 unencrypted and while it's obvious for the browser that the HTTPS
2891 request is already blocked by the proxy, some warn about unauthenticated
2895 To work around the problem you can redirect those requests to an invalid
2896 local address instead of blocking them. While the redirects aren't
2897 encrypted either, many browsers don't care. They simply follow the
2898 redirect, fail to reach a server and display an error message instead
2902 To do that, enable logging to figure out which requests get blocked by
2903 &my-app; and add the hosts (no path patterns) to a section like this:
2908 {+redirect{http://127.0.0.1:0/} -block -limit-connect}
2914 Additionally you have to configure your browser to contact
2915 <quote>127.0.0.1:0</quote> directly (instead of through &my-app;).
2918 To add a proxy exception in <application>Mozilla Firefox</application>
2919 open the <quote>Preferences</quote>, click the <quote>Settings</quote>
2920 button located on the <quote>Network</quote> tab in the <quote>Advanced</quote>
2921 section, and add <quote>127.0.0.1:0</quote> in the <quote>No Proxy for:</quote>
2927 <sect2 renderas="sect3" id="se-linux">
2928 <title>I get selinux error messages. How can I fix this?</title>
2930 Please report the problem to the creator of your selinux policies.
2933 The problem is that some selinux policy writers aren't familiar
2934 with the application they are trying to <quote>secure</quote> and
2935 thus create policies that make no sense.
2938 In <application>Privoxy's</application> case the problem usually
2939 is that the policy only allows outgoing connections for certain
2940 destination ports (e.g. 80 and 443). While this may cover the
2941 standard ports, websites occasionally use other ports as well.
2942 This isn't a security problem and therefore <application>Privoxy's</application>
2943 default configuration doesn't block these requests.
2946 If you really want to block these ports (and don't be able
2947 to load websites that don't use standard ports), you should
2948 configure Privoxy to block these ports as well, so it doesn't
2949 trigger the selinux warnings.
2954 <sect2 renderas="sect3" id="gentoo-ricers">
2955 <title>I compiled &my-app; with Gentoo's portage and it appears to be very slow. Why?</title>
2957 Probably you unintentionally compiled &my-app; without threading support
2958 in which case requests have to be serialized and only one can be served
2962 Check your <quote>USE</quote> flags and make sure they include
2963 <quote>threads</quote>. If they don't, add the flag and rebuild &my-app;.
2966 If you compiled &my-app; with threading support (on POSIX-based systems),
2967 the <quote>Conditional #defines</quote> section on <ulink
2968 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2969 will list <quote>FEATURE_PTHREAD</quote> as <quote>enabled</quote>.
2973 <sect2 renderas="sect3" id="tainted-sockets">
2974 <title>What are tainted sockets and how do I prevent them?</title>
2976 &my-app; marks sockets as tainted when it can't use them to
2977 serve additional requests.
2978 This does not necessarily mean that something went wrong and
2979 information about tainted sockets is only logged if connection
2980 debugging is enabled (debug 2).
2983 For example server sockets that were used for CONNECT requests
2984 (which are used to tunnel https:// requests) are considered tainted
2985 once the client closed its connection to &my-app;.
2986 Technically &my-app; could keep the connection to the server open,
2987 but the server would not accept requests that do not belong to the
2988 previous TLS/SSL session (and the client may even have terminated
2992 Server sockets are also marked tainted when a client requests a
2993 resource, but closes the connection before &my-app; has completely
2994 received (and forwarded) the resource to the client.
2995 In this case the server would (probably) accept additional requests,
2996 but &my-app; could not get the response without completely reading
2997 the leftovers from the previous response.
3000 These are just two examples, there are currently a bit more than
3001 25 scenarios in which a socket is considered tainted.
3004 While sockets can also be marked tainted as a result of a technical
3005 problem that may be worth fixing, the problem will be explicitly
3010 <sect2 renderas="sect3" id="pcre-stack-limit">
3011 <title>After adding my custom filters, &my-app; crashes when visitting certain websites</title>
3013 This can happen if your custom filters require more memory than &my-app;
3015 Usually the problem is that the operating system enforces a stack size limit
3016 that isn't sufficient.
3019 Unless the problem occurs with the filters available in the default configuration,
3020 this is not considered a Privoxy bug.
3023 To prevent the crashes you can rewrite your filter to use less ressources,
3024 increase the relevant memory limit or recompile pcre to use less stack space.
3025 For details please see the
3026 <ulink url="http://pcre.org/original/doc/html/pcrestack.html">pcrestack man page</ulink>
3027 and the documentation of your operating system.
3033 <!-- ~~~~~ New section ~~~~~ -->
3034 <sect1 id="contact"><title>Contacting the developers, Bug Reporting and Feature Requests</title>
3035 <!-- Include contacting.sgml -->
3037 <!-- end contacting -->
3040 <!-- ~~~~~ New section ~~~~~ -->
3041 <sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
3043 <!-- Include copyright.sgml -->
3049 Portions of this document are <quote>borrowed</quote> from the original
3050 <application>Junkbuster</application> (tm) FAQ, and modified as
3051 appropriate for <application>Privoxy</application>.
3054 <!-- ~~~~~ New section ~~~~~ -->
3055 <sect2><title>License</title>
3056 <!-- Include copyright.sgml: -->
3058 <!-- end copyright -->
3060 <!-- ~ End section ~ -->
3062 <!-- ~~~~~ New section ~~~~~ -->
3063 <sect2><title>History</title>
3064 <!-- Include history.sgml -->
3070 <!-- ~ End section ~ -->
3073 <!-- ~~~~~ New section ~~~~~ -->
3075 <sect1 id="seealso"><title>See also</title>
3077 <!-- Include seealso.sgml -->
3087 This program is free software; you can redistribute it
3088 and/or modify it under the terms of the GNU General
3089 Public License as published by the Free Software
3090 Foundation; either version 2 of the License, or (at
3091 your option) any later version.
3093 This program is distributed in the hope that it will
3094 be useful, but WITHOUT ANY WARRANTY; without even the
3095 implied warranty of MERCHANTABILITY or FITNESS FOR A
3096 PARTICULAR PURPOSE. See the GNU General Public
3097 License for more details.
3099 The GNU General Public License should be included with
3100 this file. If not, you can view it at
3101 http://www.gnu.org/copyleft/gpl.html
3102 or write to the Free Software Foundation, Inc.,
3103 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
projects / privoxy.git / blob