Why use deflate instead of gzip for text files served by Apache? The simple answer is don't. RFC 2616 defines deflate as: deflate The "zlib" format defined in RFC 1950 in combination with the "deflate" compression mechanism described in RFC 1951 The zlib format is defined in RFC 1950 as : 0 1 +---+---+ |CMF|FLG| (more-->) +---+---+ 0 1 2 3 +---+---+---+---+ | DICTID | (more-->) +---+---+---+---+ +