Google has Introduced Page Speed, an open-source Firefox/Firebug Add-on. Webmasters and web developers can use Page Speed to evaluate the performance of their web pages and to get suggestions on how to improve them.
Google Page speed is very much in analogy of Yahoo’s YSlow a similar Firefox/Firebug plugin which analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages, although google come late with such thing nevertheless Google’s Page Speed provide bit more in-depth analysis than YSlow.
Page Speed performs several tests on a site’s web server configuration and front-end code. These tests are based on a set of best practices known to enhance web page performance. Webmasters who run Page Speed on their pages get a set of scores for each page, as well as helpful suggestions on how to improve its performance.