Editing Proxy server (section)

===Web proxy servers===
Web proxies forward [[Hypertext Transfer Protocol|HTTP]] requests. The request from the client is the same as a [[Hypertext Transfer Protocol#HTTP/1.1 example of request / response transaction|regular HTTP request]] except the full URL is passed, instead of just the path.<ref name="rfc7230.5.3.2">{{cite IETF |title=HTTP/1.1 Message Syntax and Routing |quote=a client MUST send the target URI in absolute-form as the request-target |rfc=7230 |sectionname=absolute-form |section=5.3.2 |page=41 |date=June 2014 |publisher=[[Internet Engineering Task Force|IETF]] |access-date=4 November 2017 }}</ref>

<syntaxhighlight lang="http">
GET https://en.wikipedia.org/wiki/Proxy_server HTTP/1.1
Proxy-Authorization: Basic encoded-credentials
Accept: text/html

</syntaxhighlight>

This request is sent to the proxy server, the proxy makes the request specified and returns the response.
<syntaxhighlight lang="http">
HTTP/1.1 200 OK
Content-Type: text/html; charset UTF-8

</syntaxhighlight>

Some web proxies allow the [[HTTP tunnel#HTTP CONNECT method|HTTP CONNECT]] method to set up forwarding of arbitrary data through the connection; a common policy is to only forward port 443 to allow [[HTTPS]] traffic.

Examples of web proxy servers include [[Apache HTTP Server|Apache]] (with [[mod_proxy]] or [[Traffic Server]]), [[HAProxy]], [[Internet Information Services|IIS]] configured as proxy (e.g., with Application Request Routing), [[Nginx]], [[Privoxy]], [[Squid (software)|Squid]], [[Varnish (software)|Varnish]] (reverse proxy only), [[WinGate]], [[Ziproxy]], Tinyproxy, RabbIT and [[Polipo]].

For clients, the problem of complex or multiple proxy-servers is solved by a client-server [[Proxy auto-config]] protocol (''PAC file'').