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42 <h1 class="SECT1"><a name="GENERAL" id="GENERAL">1. General
46 <h3 class="SECT2"><a name="WHO-USES" id="WHO-USES">1.1. Who should give
47 <span class="APPLICATION">Privoxy</span> a try?</a></h3>
49 <p>Anyone who is interested in security, privacy, or in finer-grained
50 control over their web and Internet experience.</p>
54 <h3 class="SECT2"><a name="BESTCHOICE" id="BESTCHOICE">1.2. Is Privoxy
55 the best choice for me?</a></h3>
57 <p><span class="APPLICATION">Privoxy</span> is certainly a good choice,
58 especially for those who want more control and security. Those with the
59 willingness to read the documentation and the ability to fine-tune
60 their installation will benefit the most.</p>
62 <p>One of <span class="APPLICATION">Privoxy's</span> strengths is that
63 it is highly configurable giving you the ability to completely
64 personalize your installation. Being familiar with, or at least having
65 an interest in learning about <a href=
66 "http://en.wikipedia.org/wiki/Http" target="_top">HTTP</a> and other
67 networking protocols, <a href="http://en.wikipedia.org/wiki/Html"
68 target="_top">HTML</a>, and <a href=
69 "http://en.wikipedia.org/wiki/Regular_expressions" target=
70 "_top"><span class="QUOTE">"Regular Expressions"</span></a> will be a
71 big plus and will help you get the most out of <span class=
72 "APPLICATION">Privoxy</span>. A new installation just includes a very
73 basic configuration. The user should take this as a starting point
74 only, and enhance it as he or she sees fit. In fact, the user is
75 encouraged, and expected to, fine-tune the configuration.</p>
77 <p>Much of <span class="APPLICATION">Privoxy's</span> configuration can
78 be done with a <a href="http://en.wikipedia.org/wiki/Web_browser"
79 target="_top">Web browser</a>. But there are areas where configuration
80 is done using a <a href="http://en.wikipedia.org/wiki/Text_editors"
81 target="_top">text editor</a> to edit configuration files. Also note
82 that the web-based action editor doesn't use authentication and should
83 only be enabled in environments where all clients with access to
84 <span class="APPLICATION">Privoxy</span> listening port can be
89 <h3 class="SECT2"><a name="PROXYMORON" id="PROXYMORON">1.3. What is a
90 <span class="QUOTE">"proxy"</span>? How does Privoxy work?</a></h3>
92 <p>A <a href="http://en.wikipedia.org/wiki/Proxy_server" target=
93 "_top">web proxy</a> is a service, based on a software such as
94 <span class="APPLICATION">Privoxy</span>, that clients (i.e. browsers)
95 can use instead of connecting to web servers directly. The clients then
96 ask the proxy to request objects (web pages, images, movies etc) on
97 their behalf and to forward the data to the clients. It is a
98 <span class="QUOTE">"go-between"</span>. For details, see <a href=
99 "http://en.wikipedia.org/wiki/Proxy_server" target="_top">Wikipedia's
100 proxy definition</a>.</p>
102 <p>There are many reasons to use web proxies, such as security
103 (firewalling), efficiency (caching) and others, and there are any
104 number of proxies to accommodate those needs.</p>
106 <p><span class="APPLICATION">Privoxy</span> is a proxy that is
107 primarily focused on privacy enhancement, ad and junk elimination and
108 freeing the user from restrictions placed on his activities. Sitting
109 between your browser(s) and the Internet, it is in a perfect position
110 to filter outbound personal information that your browser is leaking,
111 as well as inbound junk. It uses a variety of techniques to do this,
112 all of which are under your complete control via the various
113 configuration files and options. Being a proxy also makes it easier to
114 share configurations among multiple browsers and/or users.</p>
118 <h3 class="SECT2"><a name="OTHERSTUFF" id="OTHERSTUFF">1.4. Does
119 Privoxy do anything more than ad blocking?</a></h3>
121 <p>Yes, ad blocking is but one possible use. There are many, many ways
122 <span class="APPLICATION">Privoxy</span> can be used to sanitize and
123 customize web browsing.</p>
127 <h3 class="SECT2"><a name="NEWJB" id="NEWJB">1.5. What is this new
128 version of <span class="QUOTE">"Junkbuster"</span>?</a></h3>
130 <p>A long time ago, there was the <span class="APPLICATION">Internet
131 Junkbuster</span>, by Anonymous Coders and Junkbusters Corporation.
132 This saved many users a lot of pain in the early days of web
133 advertising and user tracking.</p>
135 <p>But the web, its protocols and standards, and with it, the
136 techniques for forcing ads on users, give up autonomy over their
137 browsing, and for tracking them, keeps evolving. Unfortunately, the
138 <span class="APPLICATION">Internet Junkbuster</span> did not. Version
139 2.0.2, published in 1998, was the last official release, available from
140 Junkbusters Corporation. Fortunately, it had been released under the
141 GNU <a href="http://www.gnu.org/licenses/old-licenses/gpl-2.0.html"
142 target="_top">GPL</a>, which allowed further development by others.</p>
144 <p>So Stefan Waldherr started maintaining an improved version of the
145 software, to which eventually a number of people contributed patches.
146 It could already replace banners with a transparent image, and had a
147 first version of pop-up killing, but it was still very closely based on
148 the original, with all its limitations, such as the lack of HTTP/1.1
149 support, flexible per-site configuration, or content modification. The
150 last release from this effort was version 2.0.2-10, published in
153 <p>Then, some <a href=
154 "https://www.privoxy.org/user-manual/copyright.html#AUTHORS" target=
155 "_top">developers</a> picked up the thread, and started turning the
156 software inside out, upside down, and then reassembled it, adding many
158 "https://www.privoxy.org/user-manual/introduction.html#FEATURES"
159 target="_top">new features</a> along the way.</p>
161 <p>The result of this is <span class="APPLICATION">Privoxy</span>,
162 whose first stable version, 3.0, was released August, 2002.</p>
164 <p>As of 2012 the Junkbusters Corporation's website
165 (http://www.junkbusters.com/) has been shut down, but Privoxy is still
166 actively maintained.</p>
170 <h3 class="SECT2"><a name="WHYPRIVOXY" id="WHYPRIVOXY">1.6. Why
171 <span class="QUOTE">"Privoxy"</span>? Why change the name from
172 Junkbuster at all?</a></h3>
174 <p>Though outdated, Junkbusters Corporation continued to offer their
175 original version of the <span class="APPLICATION">Internet
176 Junkbuster</span> for a while, so publishing our <span class=
177 "APPLICATION">Junkbuster</span>-derived software under the same name
178 would have led to confusion.</p>
180 <p>There were also potential legal reasons not to use the <span class=
181 "APPLICATION">Junkbuster</span> name, as it was (and maybe still is) a
182 registered trademark of Junkbusters Corporation. There were, however,
183 no objections from Junkbusters Corporation to the <span class=
184 "APPLICATION">Privoxy</span> project itself, and they, in fact, shared
185 our ideals and goals.</p>
187 <p>The Privoxy developers also believed that there were so many
188 improvements over the original code, that it was time to make a clean
189 break from the past and make a name in their own right.</p>
191 <p><span class="APPLICATION">Privoxy</span> is the <span class=
192 "QUOTE">"<span class="emphasis"><i class="EMPHASIS">Privacy Enhancing
193 Proxy</i></span>"</span>. Also, its content modification and junk
194 suppression gives <span class="emphasis"><i class=
195 "EMPHASIS">you</i></span>, the user, more control, more freedom, and
196 allows you to browse your personal and <span class=
197 "QUOTE">"<span class="emphasis"><i class="EMPHASIS">private</i></span>
198 edition"</span> of the web.</p>
202 <h3 class="SECT2"><a name="DIFFERS" id="DIFFERS">1.7. How does Privoxy
203 differ from the old Junkbuster?</a></h3>
205 <p><span class="APPLICATION">Privoxy</span> picks up where <span class=
206 "APPLICATION">Junkbuster</span> left off. <span class=
207 "APPLICATION">Privoxy</span> still blocks ads and banners, still
208 manages <a href="http://en.wikipedia.org/wiki/Browser_cookie" target=
209 "_top">cookies</a>, and still helps protect your privacy. But, most of
210 these features have been enhanced, and many new ones have been added,
211 all in the same vein.</p>
213 <p><span class="APPLICATION">Privoxy</span>'s new features include:</p>
217 <p>Supports "Connection: keep-alive". Outgoing connections can be
218 kept alive independently from the client.</p>
222 <p>Supports IPv6, provided the operating system does so too, and
223 the configure script detects it.</p>
227 <p>Supports tagging which allows to change the behaviour based on
228 client and server headers.</p>
232 <p>Can be run as an "intercepting" proxy, which obviates the need
233 to configure browsers individually.</p>
237 <p>Sophisticated actions and filters for manipulating both server
238 and client headers.</p>
242 <p>Can be chained with other proxies.</p>
246 <p>Integrated browser-based configuration and control utility at
247 <a href="http://config.privoxy.org/" target=
248 "_top">http://config.privoxy.org/</a> (shortcut: <a href=
249 "http://p.p/" target="_top">http://p.p/</a>). Browser-based tracing
250 of rule and filter effects. Remote toggling.</p>
254 <p>Web page filtering (text replacements, removes banners based on
255 size, invisible <span class="QUOTE">"web-bugs"</span> and HTML
256 annoyances, etc.)</p>
260 <p>Modularized configuration that allows for standard settings and
261 user settings to reside in separate files, so that installing
262 updated actions files won't overwrite individual user settings.</p>
266 <p>Support for Perl Compatible Regular Expressions in the
267 configuration files, and a more sophisticated and flexible
268 configuration syntax.</p>
272 <p>GIF de-animation.</p>
276 <p>Bypass many click-tracking scripts (avoids script
281 <p>User-customizable HTML templates for most proxy-generated pages
282 (e.g. "blocked" page).</p>
286 <p>Auto-detection and re-reading of config file changes.</p>
290 <p>Most features are controllable on a per-site or per-location
295 <p>Many smaller new features added, limitations and bugs
302 <h3 class="SECT2"><a name="WHATSANAD" id="WHATSANAD">1.8. How does
303 Privoxy know what is an ad, and what is not?</a></h3>
305 <p><span class="APPLICATION">Privoxy</span>'s approach to blocking ads
308 <p>First, there are certain patterns in the <span class=
309 "emphasis"><i class="EMPHASIS">locations</i></span> (URLs) of banner
310 images. This applies to both the path (you wouldn't guess how many web
311 sites serve their banners from a directory called <span class=
312 "QUOTE">"banners"</span>!) and the host (blocking the big banner
313 hosting services like doublecklick.net already helps a lot).
314 <span class="APPLICATION">Privoxy</span> takes advantage of this fact
315 by using <a href="../user-manual/actions-file.html#AF-PATTERNS" target=
316 "_top">URL patterns</a> to sort out and block the requests for things
317 that sound like they would be ads or banners.</p>
319 <p>Second, banners tend to come in certain <span class=
320 "emphasis"><i class="EMPHASIS">sizes</i></span>. But you can't tell the
321 size of an image by its URL without downloading it, and if you do, it's
322 too late to save bandwidth. Therefore, <span class=
323 "APPLICATION">Privoxy</span> also inspects the HTML sources of web
324 pages while they are loaded, and replaces references to images with
325 standard banner sizes by dummy references, so that your browser doesn't
326 request them anymore in the first place.</p>
328 <p>Both of this involves a certain amount of guesswork and is, of
329 course, freely and readily configurable.</p>
333 <h3 class="SECT2"><a name="MISTAKES" id="MISTAKES">1.9. Can Privoxy
334 make mistakes? This does not sound very scientific.</a></h3>
336 <p>Actually, it's a black art ;-) And yes, it is always possible to
337 have a broad rule accidentally block or change something by mistake.
338 You will almost surely run into such situations at some point. It is
339 tricky writing rules to cover every conceivable possibility, and not
340 occasionally get false positives.</p>
342 <p>But this should not be a big concern since the <span class=
343 "APPLICATION">Privoxy</span> configuration is very flexible, and
344 includes tools to help identify these types of situations so they can
345 be addressed as needed, allowing you to customize your installation.
346 (<a href="trouble.html#BADSITE">See the Troubleshooting section
351 <h3 class="SECT2"><a name="CONFIGORNOT" id="CONFIGORNOT">1.10. Will I
352 have to configure Privoxy before I can use it?</a></h3>
354 <p>That depends on your expectations. The default installation should
355 give you a good starting point, and block <span class=
356 "emphasis"><i class="EMPHASIS">most</i></span> ads and unwanted
357 content, but many of the more advanced features are off by default, and
358 require you to activate them.</p>
360 <p>You do have to set up your browser to use <span class=
361 "APPLICATION">Privoxy</span> (see the <a href=
362 "installation.html#FIRSTSTEP">Installation section below</a>).</p>
364 <p>And you will certainly run into situations where there are false
365 positives, or ads not being blocked that you may not want to see. In
366 these cases, you would certainly benefit by customizing <span class=
367 "APPLICATION">Privoxy's</span> configuration to more closely match your
368 individual situation. And we encourage you to do this. This is where
369 the real power of <span class="APPLICATION">Privoxy</span> lies!</p>
373 <h3 class="SECT2"><a name="LAN" id="LAN">1.11. Can Privoxy run as a
374 server on a network?</a></h3>
376 <p>Yes, <span class="APPLICATION">Privoxy</span> runs as a server
377 already, and can easily be configured to <span class=
378 "QUOTE">"serve"</span> more than one client. See <a href=
379 "configuration.html#LANCONFIG">How can I set up Privoxy to act as a
380 proxy for my LAN</a> below.</p>
384 <h3 class="SECT2"><a name="BROWSERS2" id="BROWSERS2">1.12. My browser
385 does the same things as Privoxy. Why should I use Privoxy at
388 <p>Modern browsers do indeed have <span class="emphasis"><i class=
389 "EMPHASIS">some</i></span> of the same functionality as <span class=
390 "APPLICATION">Privoxy</span>. Maybe this is adequate for you. But
391 <span class="APPLICATION">Privoxy</span> is very versatile and
392 powerful, and can probably do a number of things your browser just
395 <p>In addition, a proxy is good choice if you use multiple browsers, or
396 have a LAN with multiple computers since <span class=
397 "APPLICATION">Privoxy</span> can run as a server application. This way
398 all the configuration is in one place, and you don't have to maintain a
399 similar configuration for possibly many browsers or users.</p>
401 <p>Note, however, that it's recommended to leverage both your browser's
402 and <span class="APPLICATION">Privoxy's</span> privacy enhancing
403 features at the same time. While your browser probably lacks some
404 features <span class="APPLICATION">Privoxy</span> offers, it should
405 also be able to do some things more reliably, for example restricting
406 and suppressing JavaScript.</p>
410 <h3 class="SECT2"><a name="WHYTRUST" id="WHYTRUST">1.13. Why should I
411 trust Privoxy?</a></h3>
413 <p>The most important reason is because you have access to <span class=
414 "emphasis"><i class="EMPHASIS">everything</i></span>, and you can
415 control everything. You can check every line of every configuration
416 file yourself. You can check every last bit of source code should you
417 desire. And even if you can't read code, there should be some comfort
418 in knowing that other people can, and do read it. You can build the
419 software from scratch, if you want, so that you know the executable is
420 clean, and that it is <span class="emphasis"><i class=
421 "EMPHASIS">yours</i></span>. In fact, we encourage this level of
422 scrutiny. It is one reason we use <span class=
423 "APPLICATION">Privoxy</span> ourselves.</p>
427 <h3 class="SECT2"><a name="LICENSE" id="LICENSE">1.14. Is there is a
428 license or fee? What about a warranty? Registration?</a></h3>
430 <p><span class="APPLICATION">Privoxy</span> is free software and
431 licensed under the <a href=
432 "http://www.gnu.org/licenses/old-licenses/gpl-2.0.html" target=
433 "_top">GNU General Public License (GPL) version 2</a>. It is free to
434 use, copy, modify or distribute as you wish under the terms of this
435 license. Please see the <a href="copyright.html">Copyright</a> section
436 for more information on the license and copyright. Or the <tt class=
437 "FILENAME">LICENSE</tt> file that should be included.</p>
439 <p>There is <span class="emphasis"><i class="EMPHASIS">no
440 warranty</i></span> of any kind, expressed, implied or otherwise. That
441 is something that would cost real money ;-) There is no registration
446 <h3 class="SECT2"><a name="SPYWARE" id="SPYWARE">1.15. Can Privoxy
447 remove spyware? Adware? Viruses?</a></h3>
449 <p>No, at least not reliably enough to trust it. <span class=
450 "APPLICATION">Privoxy</span> is not designed to be a malware removal
451 tool and the default configuration doesn't even try to filter out any
454 <p><span class="APPLICATION">Privoxy</span> could help prevent contact
455 from (known) sites that use such tactics with appropriate configuration
456 rules, and thus could conceivably prevent contamination from such
457 sites. However, keeping such a configuration up to date would require a
458 lot of time and effort that would be better spend on keeping your
459 software itself up to date so it doesn't have known
464 <h3 class="SECT2"><a name="OTHERADS" id="OTHERADS">1.16. Can I use
465 Privoxy with other ad-blocking software?</a></h3>
467 <p><span class="APPLICATION">Privoxy</span> should work fine with other
468 proxies and other software in general.</p>
470 <p>But it is probably not necessary to use <span class=
471 "APPLICATION">Privoxy</span> in conjunction with other ad-blocking
472 products, and this could conceivably cause undesirable results. It
473 might be better to choose one software or the other and work a little
474 to tweak its configuration to your liking.</p>
476 <p>Note that this is an advice specific to ad blocking.</p>
480 <h3 class="SECT2"><a name="HELP-THE-DEVELOPERS" id=
481 "HELP-THE-DEVELOPERS">1.17. I would like to help you, what can I
485 <h4 class="SECT3"><a name="PARTICIPATE" id="PARTICIPATE">1.17.1.
486 Would you like to participate?</a></h4>
488 <p>Well, we <span class="emphasis"><i class=
489 "EMPHASIS">always</i></span> need help. There is something for
490 everybody who wants to help us. We welcome new developers, packagers,
491 testers, documentation writers or really anyone with a desire to help
492 in any way. You <span class="emphasis"><i class="EMPHASIS">DO
493 NOT</i></span> need to be a <span class="QUOTE">"programmer"</span>.
494 There are many other tasks available. In fact, the programmers often
495 can't spend as much time programming because of some of the other,
496 more mundane things that need to be done, like checking the Tracker
497 feedback sections or responding to user questions on the mailing
500 <p>So first thing, subscribe to the <a href=
501 "https://lists.privoxy.org/mailman/listinfo/privoxy-users" target=
502 "_top">Privoxy Users</a> or the <a href=
503 "https://lists.privoxy.org/mailman/listinfo/privoxy-devel" target=
504 "_top">Privoxy Developers</a> mailing list, join the discussion, help
505 out other users, provide general feedback or report problems you
508 <p>If you intend to help out with the trackers, you also might want
509 to <a href="https://sourceforge.net/user/registration" target=
510 "_top">get an account on SourceForge.net</a> so we don't confuse you
511 with the other name-less users.</p>
513 <p>We also have a <a href="../developer-manual/index.html" target=
514 "_top">Developer's Manual</a>. While it is partly out of date, it's
515 still worth reading.</p>
518 "http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup"
519 target="_top">TODO list</a> may be of interest to you as well. Please
520 let us know if you want to work on one of the items listed.</p>
524 <h4 class="SECT3"><a name="DONATE" id="DONATE">1.17.2. Would you like
527 <p>Donations are welcome. Our <a href=
528 "http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup"
529 target="_top">TODO list</a> is rather long and being able to pay one
530 (or more) developers to work on Privoxy would make a huge difference,
531 even if it was only for a couple of weeks. Donations may also be used
532 for Privoxy-related travel expenses (for example to attend
533 conferences), for hardware used for Privoxy development and for
534 hosting expenses etc.</p>
536 <p><span class="APPLICATION">Privoxy</span> is an associated project
537 of <a href="http://www.spi-inc.org/" target="_top">Software in the
538 Public Interest (SPI)</a>, which allows us to receive tax-deductible
539 donations in the United States. If you want to donate through SPI,
540 please use <a href="http://www.spi-inc.org/donations" target=
541 "_top">SPI's donation page</a> to see what the options are.</p>
543 <p>You can also donate to Privoxy using a bank account or a "Paypal"
546 <p class="LITERALLAYOUT">
547 Name on account: <a href=
548 "https://www.zwiebelfreunde.de/" target="_top">Zwiebelfreunde
550 IBAN: DE95430609671126825604<br>
551 BIC: GENODEM1GLS<br>
552 Bank: GLS Bank</p>
554 <p class="LITERALLAYOUT">
555 "Paypal" address: privoxy@zwiebelfreunde.de</p>
557 <p>Donations made through Zwiebelfreunde e.V. are tax-deductible in
558 Germany and other countries that recognize German charitable clubs.
559 Feel free to use the Subject field to provide a name to be credited
560 and a list of TODO list items you are interested in the most. For
561 example: Max Mustermann: #16, #1, #14.</p>
563 <p>Note that donations made through Zwiebelfreunde e.V. currently
564 can't be checked automatically so you may not get credited right
565 away. The credits currently reflect donations received before
568 <p>If you have any questions regarding donations please mail to
569 either the public user mailing list or, if it's a private matter, to
570 <a href="mailto:fk@fabiankeil.de" target="_top">Fabian Keil</a>
571 (Privoxy's SPI liaison) directly.</p>
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