The ngx_http_gzip_static_module module allows to send precompressed files with the “.gz” filename extension instead of regular files.

This module is not built by default, it should be enabled with the --with-http_gzip_static_module configuration parameter.

gzip_static  on;
gzip_proxied expired no-cache no-store private auth;

gzip_static off;

Enables (“on”) or disables (“off”) checking the existence of precompressed files. The following directives are also taken into account: gzip_http_version, gzip_proxied, gzip_disable, and gzip_vary.

With the “always” value (1.3.6), gzipped file is used in all cases, without checking if the client supports it. It is useful if there are no uncompressed files on the disk anyway or the ngx_http_gunzip_module is used.

The files can be compressed using the gzip command, or any other compatible. It is recommended that the modification date and time of original and compressed files be the same.