Mod_Gzip is an external extension module for Apache web servers implemented to help with size reduction of web pages served over HTTP.

Mod_Gzip is installed on all SiteGround servers and in order to use it you need to add the following options in an .htaccess file for your hosting account:

<IfModule mod_gzip.c>
mod_gzip_static_suffix .gz
AddEncoding gzip .gz
AddEncoding gzip .gzip
mod_gzip_on YES
mod_gzip_handle_methods GET
mod_gzip_temp_dir /tmp
mod_gzip_can_negotiate Yes
mod_gzip_dechunk Yes
mod_gzip_send_vary On
mod_gzip_update_static No
mod_gzip_keep_workfiles No
mod_gzip_minimum_file_size 250
mod_gzip_maximum_file_size 1048576
mod_gzip_maximum_inmem_size 60000
mod_gzip_min_http 1000
mod_gzip_item_exclude reqheader "User-agent: Mozilla/4.0[678]"
mod_gzip_item_exclude file .js$
mod_gzip_item_exclude file .css$
mod_gzip_item_exclude mime ^application/pdf$
mod_gzip_item_exclude mime ^image/
mod_gzip_item_exclude mime ^application/x-javascript$
mod_gzip_item_include mime ^text/.*
mod_gzip_item_include file .html$
mod_gzip_item_include file .pl$
mod_gzip_item_include file .cgi$
mod_gzip_item_include handler ^cgi-script$
mod_gzip_item_include mime ^httpd/unix-directory$
mod_gzip_item_include mime ^application/postscript$
</IfModule>

Once you have added the options above you will be able to use Mod_Gzip for your website.