HTTP compression is a capability built into both web servers and web browsers, to make better use of available bandwidth. HTTP protocol data is compressed before it is sent from the server: compliant browsers will announce what methods are supported to the server before downloading the correct format; unsupported browsers will download uncompressed data. Data is usually compressed with either deflate or gzip modules specific to the server software.

Servers that support HTTP compression

• Microsoft IIS: built-in or using 3rd-party module
• Apache HTTP Server, via mod_deflate or mod_gzip
• Caucho Resin Professional, via GzipFilter
• Sun Java System Web Server
• Zeus Web Server
• Lighttpd, via mod_compress^[1]
• Nginx - built-in
• RaidenHTTPD - built-in
• Serenity Server - built-in.

External links

• RFC 2616
• Apache: mod_deflate & mod_gzip
• Compression with lighttpd
• 15 Seconds: Web Site Compression
• HTTP Compression: resource page by the founder of VIGOS AG, Constantin Rack
• Using HTTP Compression by Martin Brown of Server Watch
• Using HTTP Compression in IIS 6.0: Microsoft page
• Enabling HTTP Compression in IIS 6.0: detailed article from Donnie Mack of DotNetJunkies
• ZipEnable - a 3rd-party compression module for IIS6
• Caucho Resin Professional GzipFilter configuration
• jetNEXUS for IIS compression module - Advanced browser compatibility rule base
• 3rd-party IIS module vendor with free testing for HTTP compression results
• IISxpress: 3rd-party compression module for IIS, free for non-commercial use
• httpZip- a 3rd-party compression module for IIS 5+

Notes

1. ↑ Lighttpd's mod_compress only supports compressing static files, that is, no content dynamically generated from a cgi/fcgi/other program. mod_deflate is a modified version of mod_compress which supports dynamic content compression but it's planned for Lighttpd 1.5.0 which is still under development.