<span class="mw-page-title-main">Squid (software)</span>

Squid (software)

<p><b>Squid</b> is a <a href="/en/Web_cache" title="Web cache" class="wl">caching</a> and forwarding HTTP <a href="/en/Web_proxy" title="Web proxy" class="mw-redirect wl">web proxy</a>. It has a wide variety of uses, including speeding up a <a href="/en/Web_server" title="Web server" class="wl">web server</a> by caching repeated requests, caching <a href="/en/World_Wide_Web" title="World Wide Web" class="wl">web</a>, <a href="/en/Domain_Name_System" title="Domain Name System" class="wl">DNS</a> and other <a href="/en/Computer_network" title="Computer network" class="wl">computer network</a> lookups for a group of people sharing network resources, and aiding security by filtering traffic. Although primarily used for <a href="/en/HTTP" title="HTTP" class="wl">HTTP</a> and <a href="/en/File_Transfer_Protocol" title="File Transfer Protocol" class="wl">FTP</a>, Squid includes limited support for several other <a href="/en/Protocol_(computing)" title="Protocol (computing)" class="mw-redirect wl">protocols</a> including <a href="/en/Internet_Gopher" title="Internet Gopher" class="mw-redirect wl">Internet Gopher</a>, <a href="/en/Secure_Sockets_Layer" title="Secure Sockets Layer" class="mw-redirect wl">SSL</a>,<span class="mw-ref reference" id="cite_ref-6"><a href="#cite_note-6" style="counter-reset: mw-Ref 6;"><span class="mw-reflink-text">[6]</span></a></span> <a href="/en/Transport_Layer_Security" title="Transport Layer Security" class="wl">TLS</a> and <a href="/en/HTTPS" title="HTTPS" class="wl">HTTPS</a>. Squid does not support the <a href="/en/SOCKS" title="SOCKS" class="wl">SOCKS</a> protocol, unlike <a href="/en/Privoxy" title="Privoxy" class="wl">Privoxy</a>, with which Squid can be used in order to provide SOCKS support.</p>

<div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none" about="#mwt1">Caching and forwarding HTTP web proxy</div>
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<style data-mw-deduplicate="TemplateStyles:r1066479718" typeof="mw:Extension/templatestyles mw:Transclusion">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}body.skin-minerva .mw-parser-output .infobox-header,body.skin-minerva .mw-parser-output .infobox-subheader,body.skin-minerva .mw-parser-output .infobox-above,body.skin-minerva .mw-parser-output .infobox-title,body.skin-minerva .mw-parser-output .infobox-image,body.skin-minerva .mw-parser-output .infobox-full-data,body.skin-minerva .mw-parser-output .infobox-below{text-align:center}</style><div class='mobile-collapse'><header class="mobile-collapse-header mobile-collapse-btn"><b>Quick facts: Developer(s), Initial release, Stable release...</b> <span class='arrow'>▼</span></header> <table class="infobox vevent mobile-collapse-element"><caption class="infobox-title summary">Squid</caption><tbody><tr><td colspan="2" class="infobox-image logo"><span><a href="/en/File:Squid_Now.png" class="mw-file-description image media-thumb" title="Squid Project Logo" data-hash="File:Squid_Now.png"><img loading="lazy"alt="Squid Project Logo" src="//upload.wikimedia.org/wikipedia/commons/0/0b/Squid_Now.png" decoding="async" data-file-width="91" data-file-height="50" data-file-type="bitmap" height="110" width="200"></a></span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/en/Programmer" title="Programmer" class="wl">Developer(s)</a></th><td class="infobox-data">Duane Wessels, Henrik Nordström, Amos Jeffries, Alex Rousskov, Francesco Chemolli, Robert Collins, Guido Serassio and volunteers<span class="mw-ref reference" id="cite_ref-Who_looks_after_the_Squid_project?_1-0"><a href="#cite_note-Who_looks_after_the_Squid_project?-1" style="counter-reset: mw-Ref 1;"><span class="mw-reflink-text">[1]</span></a></span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Initial release</th><td class="infobox-data">July<span>&nbsp;</span>1996<span style="display:none"><span>&nbsp;</span>(<span class="bday dtstart published updated">1996-07</span>)</span></td></tr><tr style="display: none;"><td colspan="2" class="infobox-full-data"></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/en/Software_release_life_cycle" title="Software release life cycle" class="wl">Stable release</a></th><td class="infobox-data"><div style="margin:0px;">5.8<span class="mw-ref reference" id="cite_ref-wikidata-d8136a1378a981055bd1d31a3cd36cc5a35e3601-v3_2-0"><a href="#cite_note-wikidata-d8136a1378a981055bd1d31a3cd36cc5a35e3601-v3-2" style="counter-reset: mw-Ref 2;"><span class="mw-reflink-text">[2]</span></a></span><span>&nbsp;</span><span class="mw-valign-text-top"><a href="/en/Q841783?uselang=en#P348" title="Edit this on Wikidata" class="image wl"><img loading="lazy"alt="Edit this on Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" data-file-width="20" data-file-height="20" data-file-type="drawing" height="10" width="10" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x"></a></span>
   / 28 February 2023</div></td></tr><tr style="display:none"><td colspan="2">
</td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/en/Repository_(version_control)" title="Repository (version control)" class="wl">Repository</a></th><td class="infobox-data"><span class="url"><a rel="mw:ExtLink nofollow" href="http://github.com/squid-cache/squid" class="external text" target="_blank">github<wbr>.com<wbr>/squid-cache<wbr>/squid</a></span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Written in</th><td class="infobox-data"><a href="/en/C++_(programming_language)" title="C++ (programming language)" class="mw-redirect wl">C++</a><span class="mw-ref reference" id="cite_ref-3"><a href="#cite_note-3" style="counter-reset: mw-Ref 3;"><span class="mw-reflink-text">[3]</span></a></span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/en/Operating_system" title="Operating system" class="wl">Operating system</a></th><td class="infobox-data"><a href="/en/BSD" title="BSD" class="mw-redirect wl">BSD</a>, <a href="/en/Linux" title="Linux" class="wl">Linux</a>, <a href="/en/Unix" title="Unix" class="wl">Unix</a>, <a href="/en/Microsoft_Windows" title="Microsoft Windows" class="wl">Windows</a><span class="mw-ref reference" id="cite_ref-4"><a href="#cite_note-4" style="counter-reset: mw-Ref 4;"><span class="mw-reflink-text">[4]</span></a></span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/en/Software_categories#Categorization_approaches" title="Software categories" class="wl">Type</a></th><td class="infobox-data"><a href="/en/Proxy_server" title="Proxy server" class="wl">Proxy server</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/en/Software_license" title="Software license" class="wl">License</a></th><td class="infobox-data"><a href="/en/GNU_General_Public_License" title="GNU General Public License" class="wl">GPL-2.0-or-later</a><span class="mw-ref reference" id="cite_ref-Squid_License_5-0"><a href="#cite_note-Squid_License-5" style="counter-reset: mw-Ref 5;"><span class="mw-reflink-text">[5]</span></a></span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Website</th><td class="infobox-data"><span class="url"><a rel="mw:ExtLink nofollow" href="http://www.squid-cache.org" class="external text" target="_blank">www<wbr>.squid-cache<wbr>.org</a></span></td></tr></tbody></table> <footer class='mobile-collapse-footer mobile-collapse-btn'><b>Close</b> <span class='arrow'>▲</span></footer></div>

<figure class="wiki-thumb"><a href="/en/File:LAMP_software_bundle.svg" class="mw-file-description image media-thumb" data-hash="File:LAMP_software_bundle.svg"><img loading="lazy" src="//upload.wikimedia.org/wikipedia/commons/thumb/8/82/LAMP_software_bundle.svg/300px-LAMP_software_bundle.svg.png" decoding="async" data-file-width="1280" data-file-height="720" data-file-type="drawing" height="169" width="300" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/82/LAMP_software_bundle.svg/450px-LAMP_software_bundle.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/82/LAMP_software_bundle.svg/600px-LAMP_software_bundle.svg.png 2x" alt="LAMP_software_bundle.svg"></a><figcaption>The <a href="/en/LAMP_(software_bundle)" title="LAMP (software bundle)" class="wl">LAMP stack</a> with Squid as web cache.</figcaption></figure>

<p>Squid was originally designed to run as a <a href="/en/Daemon_(computer_software)" title="Daemon (computer software)" class="mw-redirect wl">daemon</a> on <a href="/en/Unix-like" title="Unix-like" class="wl">Unix-like</a> systems. A Windows port was maintained up to version 2.7. New versions available on Windows use the <a href="/en/Cygwin" title="Cygwin" class="wl">Cygwin</a> environment.<span class="mw-ref reference" id="cite_ref-7"><a href="#cite_note-7" style="counter-reset: mw-Ref 7;"><span class="mw-reflink-text">[7]</span></a></span> Squid is <a href="/en/Free_software" title="Free software" class="wl">free software</a> released under the <a href="/en/GNU_General_Public_License" title="GNU General Public License" class="wl">GNU General Public License</a>.</p>



Squid is a caching and forwarding HTTP web proxy. It has a wide variety of uses, including speeding up a web server by caching repeated requests, caching web, DNS and other computer network lookups for a group of people sharing network resources, and aiding security by filtering traffic. Although primarily used for HTTP and FTP, Squid includes limited support for several other protocols including Internet Gopher, SSL, TLS and HTTPS. Squid does not support the SOCKS protocol, unlike Privoxy, with which Squid can be used in order to provide SOCKS support. Squid was originally designed to run as a daemon on Unix-like systems. A Windows port was maintained up to version 2.7. New versions available on Windows use the Cygwin environment. Squid is free software released under the GNU General Public License. 