YSlow is a popular website optimization tool from Yahoo and it was available for Firefox as an add-on previously. The extension is now available for Google Chrome. YSlow for Chrome is essentially the same as the Firefox version in terms of features, but it differs internally since Chrome does not allow extensions to access its network panel.  YSlow grades web page based on one of three predefined ruleset or a user-defined ruleset. It offers suggestions for improving the page’s performance, summarizes the page’s components, displays statistics about the page.

Yslow

You can run multiple YSlow instances and this feature is excellent for comparing YSlow results for different pages side-by-side.

Yslow 1

YSlow for Chrome comes with three rulesets, the Default YSlow V2, Classic V1, and Small Site or Blog.

You can download YSlow for Chrome from here.