Hi, I have squid in front of tomcat servers as reverse proxy. The origin servers return some files gzipped. I can confirm this by going to them directly with header Accept-Encoding: gzip,deflate Origin server returns: HTTP/1.1 200 OK Server: Apache-Coyote/1.1 Cache-Control: max-age=1801 Accept-Ranges: bytes ETag: W/"18267-1250213328000" Last-Modified: Fri, 14 Aug 2009 01:28:48 GMT Content-Type: text/css Content-Encoding: gzip Vary: Accept-Encoding Date: Wed, 10 Mar 2010 03:58:54 GMT Connection: close If I go to squid with the same header I get the uncompressed file: HTTP/1.0 200 OK Accept-Ranges: bytes Last-Modified: Fri, 14 Aug 2009 01:28:48 GMT Content-Type: text/css Content-Length: 18267 Server: Apache-Coyote/1.1 Cache-Control: max-age=1801 ETag: W/"18267-1250213328000" Date: Wed, 10 Mar 2010 04:38:40 GMT X-Cache: HIT from www... X-Cache-Lookup: HIT from www... Via: 1.1 www...:80 (squid/2.7.STABLE6) Connection: keep-alive The only squid configuration is reverse proxy ACL for origin servers and the domains they map to, there is nothing specific to compression or headers in general. This is using the default tomcat connectors that support compression. Any ideas?