To test the compression of items in a web page we can use firebug to test individual items. Open firebug and go to Net tab. There you’ll find all the elements of the page. Expand any element and check “Response Header”. There will be so many entries as below:
Date Tue, 13 Dec 2011 05:44:53 GMT
Last-Modified Wed, 03 Aug 2011 17:53:37 GMT
Keep-Alive timeout=5, max=100
Group wise items can also be selected by using the sub tabs like html,css, js etc. XHR tab is for ajax requests. There you can check all the requests which are made dynamically using ajax.