This article will describe how you can fix the cookie-free domain issue occurred gtmetrix for WordPress website, on a Linux based server. Serving contents from cookie-free domains is a warning which you may encounter sometime while running a speed or performance test for your website using some of the tools which are available online. When you are using a test tool like Google PageSpeed Insights, Pingdom, GTmetrix for example, you may encounter this warning.
By following this tutorial you can fix the issue and help your site perform better than before.