Yahoo!'s Exceptional Performance team has identified 13 best practices for making web pages faster. These guidelines focus on the front-end, where 80-90% of the end-user response time is spent, and have proven to reduce response times of Yahoo! properties by 25-50%. This phenomenon of only 80-90% of the user response time being spent in the front-end is not isolated to just Yahoo!. It holds true for most web sites, including the 10 most-visited U.S. web sites. In any optimization effort it’s critical to profile current performance to identify where the greatest improvement can be made. It’s clear that the place to focus is front-end performance.

1. There is more potential for improvement by focusing on the front-end. Making the back-end twice as fast reduces response times by 5-10%, whereas making the front-end twice as fast saves 40-45%.
2. Front-end improvements typically require less time and resources than back-end performance projects.
3. Focusing on front-end improvements has proven to work. Over fifty teams at Yahoo! have reduced their end-user response times by following the best practices described here.

In this talk, Steve Souders will present the 13 performance best practices. He'll demonstrate Yahoo! performance tools developed in Firefox and use them to evaluate the performance of some popular web sites.