http://wiki.nginx.org/HttpGzipStaticModule Greetings! According to this page, it would seem that you can not define which mime types should be checked specifically for static gzip separately from the mime types which are compressed on-the-fly. For more control, there should be something like gzip_static_types. CSS/JS files are for the most part static, but HTML and RSS files are updateby gfx - Ideas and Feature Requests