Why using mod_gzip might be counter productive with Internet explorer

The Apache mod_gzip module allows you to GZip traffic going through HTTP server on the fly. One problem with mod_gzip and mod_deflate is that they set Vary: Accept-Encoding header and you might be setting few other Vary headers.

Now problem with IE is that if it gets any response where value of Vary header is any thing other than User-Agent and Accept-Encoding then it does not cache the response and makes a full request every time.

These two articles have details on this problem

• Internet explorer meets Vary header


• Vary with care