Enabling HTTP Compression IIS 6.0

Applies To: Windows Server 2003, Windows Server 2003 with SP1

Enabling IIS's HTTP compression feature provides faster transmission time between compression-enabled browsers and IIS regardless of whether your content is served from local storage or a UNC resource. You can compress static files only, application response files only (dynamic compression), or both static files and application response files.

Enabling compression of static files in IIS always results in more efficient utilization of bandwidth and faster Web site performance. Enabling dynamic compression always results in more efficient utilization of bandwidth as well, but if your server's processor utilization is already extremely high, the CPU load imposed by dynamic compression might make your site perform more slowly. It is therefore important to do performance testing of a server both with and without dynamic compression to determine whether dynamic compression is of benefit.

If you already have a network-based compression solution installed, enabling compression in IIS might not result in bandwidth utilization or performance improvements, depending on whether the network-based compression and IIS-based compression are redundant.

For more information about how to enable HTTP compression server-wide, see Using HTTP Compression.

For a detailed discussion of how IIS's HTTP compression works, how to test compression, and detailed compression configuration options, see Optimizing IIS 6.0 Performance.