GZIP

This is where files are zipped on the server and then uncompressed by the browser leading to faster access to the site for the viewers

To active GZIP go to System -> Global Configuration > click the Server tab -> select GZIP Page Compression and set the option to ‘Yes’ > Then save.

Be Aware

In some situations GZip can cause issues – by compressing the files it adds additional server load which can be an issue for large sites, together with some old or managed servers having Gzip not installed and/or set up incorrectly.

Then check the site and Analyse with gtmetrix.com/ to confirm its enabled and working as expected