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28 <h1 class="SECT1"><a name="GENERAL" id="GENERAL">1. General Information</a></h1>
30 <h3 class="SECT2"><a name="WHO-USES" id="WHO-USES">1.1. Who should give <span class="APPLICATION">Privoxy</span>
32 <p>Anyone who is interested in security, privacy, or in finer-grained control over their web and Internet
36 <h3 class="SECT2"><a name="BESTCHOICE" id="BESTCHOICE">1.2. Is Privoxy the best choice for me?</a></h3>
37 <p><span class="APPLICATION">Privoxy</span> is certainly a good choice, especially for those who want more
38 control and security. Those with the willingness to read the documentation and the ability to fine-tune their
39 installation will benefit the most.</p>
40 <p>One of <span class="APPLICATION">Privoxy's</span> strengths is that it is highly configurable giving you the
41 ability to completely personalize your installation. Being familiar with, or at least having an interest in
42 learning about <a href="http://en.wikipedia.org/wiki/Http" target="_top">HTTP</a> and other networking protocols,
43 <a href="http://en.wikipedia.org/wiki/Html" target="_top">HTML</a>, and <a href=
44 "http://en.wikipedia.org/wiki/Regular_expressions" target="_top"><span class="QUOTE">"Regular
45 Expressions"</span></a> will be a big plus and will help you get the most out of <span class=
46 "APPLICATION">Privoxy</span>. A new installation just includes a very basic configuration. The user should take
47 this as a starting point only, and enhance it as he or she sees fit. In fact, the user is encouraged, and
48 expected to, fine-tune the configuration.</p>
49 <p>Much of <span class="APPLICATION">Privoxy's</span> configuration can be done with a <a href=
50 "http://en.wikipedia.org/wiki/Web_browser" target="_top">Web browser</a>. But there are areas where configuration
51 is done using a <a href="http://en.wikipedia.org/wiki/Text_editors" target="_top">text editor</a> to edit
52 configuration files. Also note that the web-based action editor doesn't use authentication and should only be
53 enabled in environments where all clients with access to <span class="APPLICATION">Privoxy</span> listening port
57 <h3 class="SECT2"><a name="PROXYMORON" id="PROXYMORON">1.3. What is a <span class="QUOTE">"proxy"</span>? How
58 does Privoxy work?</a></h3>
59 <p>A <a href="http://en.wikipedia.org/wiki/Proxy_server" target="_top">web proxy</a> is a service, based on a
60 software such as <span class="APPLICATION">Privoxy</span>, that clients (i.e. browsers) can use instead of
61 connecting to web servers directly. The clients then ask the proxy to request objects (web pages, images, movies
62 etc) on their behalf and to forward the data to the clients. It is a <span class="QUOTE">"go-between"</span>. For
63 details, see <a href="http://en.wikipedia.org/wiki/Proxy_server" target="_top">Wikipedia's proxy
65 <p>There are many reasons to use web proxies, such as security (firewalling), efficiency (caching) and others,
66 and there are any number of proxies to accommodate those needs.</p>
67 <p><span class="APPLICATION">Privoxy</span> is a proxy that is primarily focused on privacy enhancement, ad and
68 junk elimination and freeing the user from restrictions placed on his activities. Sitting between your browser(s)
69 and the Internet, it is in a perfect position to filter outbound personal information that your browser is
70 leaking, as well as inbound junk. It uses a variety of techniques to do this, all of which are under your
71 complete control via the various configuration files and options. Being a proxy also makes it easier to share
72 configurations among multiple browsers and/or users.</p>
75 <h3 class="SECT2"><a name="OTHERSTUFF" id="OTHERSTUFF">1.4. Does Privoxy do anything more than ad
77 <p>Yes, ad blocking is but one possible use. There are many, many ways <span class="APPLICATION">Privoxy</span>
78 can be used to sanitize and customize web browsing.</p>
81 <h3 class="SECT2"><a name="NEWJB" id="NEWJB">1.5. What is this new version of <span class=
82 "QUOTE">"Junkbuster"</span>?</a></h3>
83 <p>A long time ago, there was the <span class="APPLICATION">Internet Junkbuster</span>, by Anonymous Coders and
84 Junkbusters Corporation. This saved many users a lot of pain in the early days of web advertising and user
86 <p>But the web, its protocols and standards, and with it, the techniques for forcing ads on users, give up
87 autonomy over their browsing, and for tracking them, keeps evolving. Unfortunately, the <span class=
88 "APPLICATION">Internet Junkbuster</span> did not. Version 2.0.2, published in 1998, was the last official
89 release, available from Junkbusters Corporation. Fortunately, it had been released under the GNU <a href=
90 "http://www.gnu.org/licenses/old-licenses/gpl-2.0.html" target="_top">GPL</a>, which allowed further development
92 <p>So Stefan Waldherr started maintaining an improved version of the software, to which eventually a number of
93 people contributed patches. It could already replace banners with a transparent image, and had a first version of
94 pop-up killing, but it was still very closely based on the original, with all its limitations, such as the lack
95 of HTTP/1.1 support, flexible per-site configuration, or content modification. The last release from this effort
96 was version 2.0.2-10, published in 2000.</p>
97 <p>Then, some <a href="https://www.privoxy.org/user-manual/copyright.html#AUTHORS" target="_top">developers</a>
98 picked up the thread, and started turning the software inside out, upside down, and then reassembled it, adding
99 many <a href="https://www.privoxy.org/user-manual/introduction.html#FEATURES" target="_top">new features</a>
101 <p>The result of this is <span class="APPLICATION">Privoxy</span>, whose first stable version, 3.0, was released
103 <p>As of 2012 the Junkbusters Corporation's website (http://www.junkbusters.com/) has been shut down, but Privoxy
104 is still actively maintained.</p>
107 <h3 class="SECT2"><a name="WHYPRIVOXY" id="WHYPRIVOXY">1.6. Why <span class="QUOTE">"Privoxy"</span>? Why change
108 the name from Junkbuster at all?</a></h3>
109 <p>Though outdated, Junkbusters Corporation continued to offer their original version of the <span class=
110 "APPLICATION">Internet Junkbuster</span> for a while, so publishing our <span class=
111 "APPLICATION">Junkbuster</span>-derived software under the same name would have led to confusion.</p>
112 <p>There were also potential legal reasons not to use the <span class="APPLICATION">Junkbuster</span> name, as it
113 was (and maybe still is) a registered trademark of Junkbusters Corporation. There were, however, no objections
114 from Junkbusters Corporation to the <span class="APPLICATION">Privoxy</span> project itself, and they, in fact,
115 shared our ideals and goals.</p>
116 <p>The Privoxy developers also believed that there were so many improvements over the original code, that it was
117 time to make a clean break from the past and make a name in their own right.</p>
118 <p><span class="APPLICATION">Privoxy</span> is the <span class="QUOTE">"<span class="emphasis"><i class=
119 "EMPHASIS">Privacy Enhancing Proxy</i></span>"</span>. Also, its content modification and junk suppression gives
120 <span class="emphasis"><i class="EMPHASIS">you</i></span>, the user, more control, more freedom, and allows you
121 to browse your personal and <span class="QUOTE">"<span class="emphasis"><i class="EMPHASIS">private</i></span>
122 edition"</span> of the web.</p>
125 <h3 class="SECT2"><a name="DIFFERS" id="DIFFERS">1.7. How does Privoxy differ from the old Junkbuster?</a></h3>
126 <p><span class="APPLICATION">Privoxy</span> picks up where <span class="APPLICATION">Junkbuster</span> left off.
127 <span class="APPLICATION">Privoxy</span> still blocks ads and banners, still manages <a href=
128 "http://en.wikipedia.org/wiki/Browser_cookie" target="_top">cookies</a>, and still helps protect your privacy.
129 But, most of these features have been enhanced, and many new ones have been added, all in the same vein.</p>
130 <p><span class="APPLICATION">Privoxy</span>'s new features include:</p>
133 <p>Supports "Connection: keep-alive". Outgoing connections can be kept alive independently from the
137 <p>Supports IPv6, provided the operating system does so too, and the configure script detects it.</p>
140 <p>Supports tagging which allows to change the behaviour based on client and server headers.</p>
143 <p>Can be run as an "intercepting" proxy, which obviates the need to configure browsers individually.</p>
146 <p>Sophisticated actions and filters for manipulating both server and client headers.</p>
149 <p>Can be chained with other proxies.</p>
152 <p>Integrated browser-based configuration and control utility at <a href="http://config.privoxy.org/" target=
153 "_top">http://config.privoxy.org/</a> (shortcut: <a href="http://p.p/" target="_top">http://p.p/</a>).
154 Browser-based tracing of rule and filter effects. Remote toggling.</p>
157 <p>Web page filtering (text replacements, removes banners based on size, invisible <span class=
158 "QUOTE">"web-bugs"</span> and HTML annoyances, etc.)</p>
161 <p>Modularized configuration that allows for standard settings and user settings to reside in separate files,
162 so that installing updated actions files won't overwrite individual user settings.</p>
165 <p>Support for Perl Compatible Regular Expressions in the configuration files, and a more sophisticated and
166 flexible configuration syntax.</p>
169 <p>GIF de-animation.</p>
172 <p>Bypass many click-tracking scripts (avoids script redirection).</p>
175 <p>User-customizable HTML templates for most proxy-generated pages (e.g. "blocked" page).</p>
178 <p>Auto-detection and re-reading of config file changes.</p>
181 <p>Most features are controllable on a per-site or per-location basis.</p>
184 <p>Many smaller new features added, limitations and bugs removed.</p>
189 <h3 class="SECT2"><a name="WHATSANAD" id="WHATSANAD">1.8. How does Privoxy know what is an ad, and what is
191 <p><span class="APPLICATION">Privoxy</span>'s approach to blocking ads is twofold:</p>
192 <p>First, there are certain patterns in the <span class="emphasis"><i class="EMPHASIS">locations</i></span>
193 (URLs) of banner images. This applies to both the path (you wouldn't guess how many web sites serve their banners
194 from a directory called <span class="QUOTE">"banners"</span>!) and the host (blocking the big banner hosting
195 services like doublecklick.net already helps a lot). <span class="APPLICATION">Privoxy</span> takes advantage of
196 this fact by using <a href="../user-manual/actions-file.html#AF-PATTERNS" target="_top">URL patterns</a> to sort
197 out and block the requests for things that sound like they would be ads or banners.</p>
198 <p>Second, banners tend to come in certain <span class="emphasis"><i class="EMPHASIS">sizes</i></span>. But you
199 can't tell the size of an image by its URL without downloading it, and if you do, it's too late to save
200 bandwidth. Therefore, <span class="APPLICATION">Privoxy</span> also inspects the HTML sources of web pages while
201 they are loaded, and replaces references to images with standard banner sizes by dummy references, so that your
202 browser doesn't request them anymore in the first place.</p>
203 <p>Both of this involves a certain amount of guesswork and is, of course, freely and readily configurable.</p>
206 <h3 class="SECT2"><a name="MISTAKES" id="MISTAKES">1.9. Can Privoxy make mistakes? This does not sound very
208 <p>Actually, it's a black art ;-) And yes, it is always possible to have a broad rule accidentally block or
209 change something by mistake. You will almost surely run into such situations at some point. It is tricky writing
210 rules to cover every conceivable possibility, and not occasionally get false positives.</p>
211 <p>But this should not be a big concern since the <span class="APPLICATION">Privoxy</span> configuration is very
212 flexible, and includes tools to help identify these types of situations so they can be addressed as needed,
213 allowing you to customize your installation. (<a href="trouble.html#BADSITE">See the Troubleshooting section
217 <h3 class="SECT2"><a name="CONFIGORNOT" id="CONFIGORNOT">1.10. Will I have to configure Privoxy before I can use
219 <p>That depends on your expectations. The default installation should give you a good starting point, and block
220 <span class="emphasis"><i class="EMPHASIS">most</i></span> ads and unwanted content, but many of the more
221 advanced features are off by default, and require you to activate them.</p>
222 <p>You do have to set up your browser to use <span class="APPLICATION">Privoxy</span> (see the <a href=
223 "installation.html#FIRSTSTEP">Installation section below</a>).</p>
224 <p>And you will certainly run into situations where there are false positives, or ads not being blocked that you
225 may not want to see. In these cases, you would certainly benefit by customizing <span class=
226 "APPLICATION">Privoxy's</span> configuration to more closely match your individual situation. And we encourage
227 you to do this. This is where the real power of <span class="APPLICATION">Privoxy</span> lies!</p>
230 <h3 class="SECT2"><a name="LAN" id="LAN">1.11. Can Privoxy run as a server on a network?</a></h3>
231 <p>Yes, <span class="APPLICATION">Privoxy</span> runs as a server already, and can easily be configured to
232 <span class="QUOTE">"serve"</span> more than one client. See <a href="configuration.html#LANCONFIG">How can I set
233 up Privoxy to act as a proxy for my LAN</a> below.</p>
236 <h3 class="SECT2"><a name="BROWSERS2" id="BROWSERS2">1.12. My browser does the same things as Privoxy. Why should
237 I use Privoxy at all?</a></h3>
238 <p>Modern browsers do indeed have <span class="emphasis"><i class="EMPHASIS">some</i></span> of the same
239 functionality as <span class="APPLICATION">Privoxy</span>. Maybe this is adequate for you. But <span class=
240 "APPLICATION">Privoxy</span> is very versatile and powerful, and can probably do a number of things your browser
242 <p>In addition, a proxy is good choice if you use multiple browsers, or have a LAN with multiple computers since
243 <span class="APPLICATION">Privoxy</span> can run as a server application. This way all the configuration is in
244 one place, and you don't have to maintain a similar configuration for possibly many browsers or users.</p>
245 <p>Note, however, that it's recommended to leverage both your browser's and <span class=
246 "APPLICATION">Privoxy's</span> privacy enhancing features at the same time. While your browser probably lacks
247 some features <span class="APPLICATION">Privoxy</span> offers, it should also be able to do some things more
248 reliably, for example restricting and suppressing JavaScript.</p>
251 <h3 class="SECT2"><a name="WHYTRUST" id="WHYTRUST">1.13. Why should I trust Privoxy?</a></h3>
252 <p>The most important reason is because you have access to <span class="emphasis"><i class=
253 "EMPHASIS">everything</i></span>, and you can control everything. You can check every line of every configuration
254 file yourself. You can check every last bit of source code should you desire. And even if you can't read code,
255 there should be some comfort in knowing that other people can, and do read it. You can build the software from
256 scratch, if you want, so that you know the executable is clean, and that it is <span class="emphasis"><i class=
257 "EMPHASIS">yours</i></span>. In fact, we encourage this level of scrutiny. It is one reason we use <span class=
258 "APPLICATION">Privoxy</span> ourselves.</p>
261 <h3 class="SECT2"><a name="LICENSE" id="LICENSE">1.14. Is there is a license or fee? What about a warranty?
262 Registration?</a></h3>
263 <p><span class="APPLICATION">Privoxy</span> is free software and licensed under the <a href=
264 "http://www.gnu.org/licenses/old-licenses/gpl-2.0.html" target="_top">GNU General Public License (GPL) version
265 2</a>. It is free to use, copy, modify or distribute as you wish under the terms of this license. Please see the
266 <a href="copyright.html">Copyright</a> section for more information on the license and copyright. Or the
267 <tt class="FILENAME">LICENSE</tt> file that should be included.</p>
268 <p>There is <span class="emphasis"><i class="EMPHASIS">no warranty</i></span> of any kind, expressed, implied or
269 otherwise. That is something that would cost real money ;-) There is no registration either.</p>
272 <h3 class="SECT2"><a name="SPYWARE" id="SPYWARE">1.15. Can Privoxy remove spyware? Adware? Viruses?</a></h3>
273 <p>No, at least not reliably enough to trust it. <span class="APPLICATION">Privoxy</span> is not designed to be a
274 malware removal tool and the default configuration doesn't even try to filter out any malware.</p>
275 <p><span class="APPLICATION">Privoxy</span> could help prevent contact from (known) sites that use such tactics
276 with appropriate configuration rules, and thus could conceivably prevent contamination from such sites. However,
277 keeping such a configuration up to date would require a lot of time and effort that would be better spend on
278 keeping your software itself up to date so it doesn't have known vulnerabilities.</p>
281 <h3 class="SECT2"><a name="OTHERADS" id="OTHERADS">1.16. Can I use Privoxy with other ad-blocking
283 <p><span class="APPLICATION">Privoxy</span> should work fine with other proxies and other software in
285 <p>But it is probably not necessary to use <span class="APPLICATION">Privoxy</span> in conjunction with other
286 ad-blocking products, and this could conceivably cause undesirable results. It might be better to choose one
287 software or the other and work a little to tweak its configuration to your liking.</p>
288 <p>Note that this is an advice specific to ad blocking.</p>
291 <h3 class="SECT2"><a name="HELP-THE-DEVELOPERS" id="HELP-THE-DEVELOPERS">1.17. I would like to help you, what can
294 <h4 class="SECT3"><a name="PARTICIPATE" id="PARTICIPATE">1.17.1. Would you like to participate?</a></h4>
295 <p>Well, we <span class="emphasis"><i class="EMPHASIS">always</i></span> need help. There is something for
296 everybody who wants to help us. We welcome new developers, packagers, testers, documentation writers or really
297 anyone with a desire to help in any way. You <span class="emphasis"><i class="EMPHASIS">DO NOT</i></span> need
298 to be a <span class="QUOTE">"programmer"</span>. There are many other tasks available. In fact, the programmers
299 often can't spend as much time programming because of some of the other, more mundane things that need to be
300 done, like checking the Tracker feedback sections or responding to user questions on the mailing lists.</p>
301 <p>So first thing, subscribe to the <a href="https://lists.privoxy.org/mailman/listinfo/privoxy-users" target=
302 "_top">Privoxy Users</a> or the <a href="https://lists.privoxy.org/mailman/listinfo/privoxy-devel" target=
303 "_top">Privoxy Developers</a> mailing list, join the discussion, help out other users, provide general feedback
304 or report problems you noticed.</p>
305 <p>If you intend to help out with the trackers, you also might want to <a href=
306 "https://sourceforge.net/user/registration" target="_top">get an account on SourceForge.net</a> so we don't
307 confuse you with the other name-less users.</p>
308 <p>We also have a <a href="../developer-manual/index.html" target="_top">Developer's Manual</a>. While it is
309 partly out of date, it's still worth reading.</p>
310 <p>Our <a href="https://www.privoxy.org/gitweb/?p=privoxy.git;a=blob_plain;f=TODO;hb=HEAD" target="_top">TODO
311 list</a> may be of interest to you as well. Please let us know if you want to work on one of the items
315 <h4 class="SECT3"><a name="DONATE" id="DONATE">1.17.2. Would you like to donate?</a></h4>
316 <p>Donations are welcome. Our <a href=
317 "https://www.privoxy.org/gitweb/?p=privoxy.git;a=blob_plain;f=TODO;hb=HEAD" target="_top">TODO list</a> is
318 rather long and being able to pay one (or more) developers to work on Privoxy would make a huge difference,
319 even if it was only for a couple of weeks. Donations may also be used for Privoxy-related travel expenses (for
320 example to attend conferences), for hardware used for Privoxy development and for hosting expenses etc.</p>
321 <p><span class="APPLICATION">Privoxy</span> is an associated project of <a href="https://www.spi-inc.org/"
322 target="_top">Software in the Public Interest (SPI)</a>, which allows us to receive tax-deductible donations in
323 the United States. You can <a href="https://www.spi-inc.org/projects/privoxy/" target="_top">donate via
324 Paypal</a> and <a href="https://co.clickandpledge.com/advanced/default.aspx?wid=34115" target="_top">Click
325 & Pledge</a>. For details, please have a look at <a href="https://www.spi-inc.org/donations" target=
326 "_top">SPI's general donation page</a>.</p>
327 <p>You can also donate to Privoxy using a bank account or a "Paypal" address:</p>
328 <p class="LITERALLAYOUT"> Name on account: <a href="https://www.zwiebelfreunde.de/" target=
329 "_top">Zwiebelfreunde e.V.</a><br>
330 IBAN: DE95430609671126825604<br>
331 BIC: GENODEM1GLS<br>
332 Bank: GLS Bank</p>
333 <p class="LITERALLAYOUT"> "Paypal" address: privoxy@zwiebelfreunde.de</p>
334 <p>Donations made through Zwiebelfreunde e.V. are tax-deductible in Germany and other countries that recognize
335 German charitable clubs. Feel free to use the Subject field to provide a name to be credited and a list of TODO
336 list items you are interested in the most. For example: Max Mustermann: #16, #1, #14.</p>
337 <p>Note that donations made through Zwiebelfreunde e.V. currently can't be checked automatically so you may not
338 get credited right away. The credits currently reflect donations received before 2016-01-14.</p>
339 <p>If you have any questions regarding donations please mail to either the public user mailing list or, if it's
340 a private matter, to <a href="mailto:fk@fabiankeil.de" target="_top">Fabian Keil</a> (Privoxy's SPI liaison)
345 <h2 class="SECT2"><a name="SPONSOR" id="SPONSOR">1.18. How can I become a sponsor and get my logo or link on
346 privoxy.org?</a></h2>
347 <p>We are currently offering the following sponsor levels as an experiment:</p>
348 <div class="VARIABLELIST">
350 <dt>Gold (10000 EUR/year)</dt>
352 <p>Logo shown at the bottom of the <a href="https://www.privoxy.org/" target="_top">Privoxy homepage</a>.
353 Logo, link and self description on the <a href="https://www.privoxy.org/sponsors/" target="_top">sponsor
356 <dt>Silver (1000 EUR/year)</dt>
358 <p>Logo shown randomly at the bottom of the <a href="https://www.privoxy.org/" target="_top">Privoxy
359 homepage</a>. Logo, link and self description on the <a href="https://www.privoxy.org/sponsors/" target=
360 "_top">sponsor page</a>.</p>
362 <dt>Bronze (500 EUR/year)</dt>
364 <p>Logo and link on the <a href="https://www.privoxy.org/sponsors/" target="_top">sponsor page</a>.</p>
368 <p>The logo sizes depend on the sponsor level. Logos are served from our server, no requests are made to the
369 sponsor website unless the links are being used.</p>
370 <p>The details may change over time but changes will only affect new sponsors (or existing sponsors that
371 explicitly agreed to the changes).</p>
372 <p>If you want to become a sponsor, please contact <a href="mailto:fk@fabiankeil.de" target="_top">Fabian
373 Keil</a>. New sponsors are only accepted if no developer objects.</p>
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