GZIP compression has serious impact on performance and your website loading time. In order to use it make sure that mod_deflate and mod_filter are enabled.

First create new file that will contain GZIP settings for Apache:

sudo vi /usr/local/apache2/conf/extra/httpd-deflate.conf

Paste there following content and save the file:

<IfModule mod_deflate.c>
<IfModule mod_filter.c>
AddOutputFilterByType DEFLATE application/ecmascript
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/rss+xml
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE application/x-javascript
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE text/plain
AddOutputFilterByType DEFLATE text/xml
</IfModule>
</IfModule>

It will add GZIP compression to most popular file types such as HTML, CSS, JS etc. If you need anything else that requires compressing, simply add more MIME types.

Now you need to include it to main Apache configuration. so open httpd.conf and Include httpd-deflate.conf.

vi /usr/local/apache2/conf/httpd.conf and make sure the following line is added.

Include conf/extra/httpd-deflate.conf