Fixit – GZip Encoding

This test determines if your page is transferred using GZip encoding. GZip encoding, or compression, reduces the data being sent and this speeds up the transfer time considerably. Where possible all web assets should use GZip encoding for transmission.

Checking for GZip encoding

This test checks to see if data is being sent with GZip encoding to limit data size and optimize transfer speed. If GZip encoding is not being used or some assets are not being transferred using it then the test reports a FAIL.

If you receive a FAIL for this test, you should consider configuring your server to deliver web assets using GZip encoding.

Reference

This test is based on a YSlow best practice. See http://yslow.org/faq/ for more details.