These rules are the key to speeding up your web pages. They've been tested on some of the most popular sites on the Internet and have successfully reduced the response times of those pages by 25-50%.

The key insight behind these best practices is the realization that only 10-20% of the total end-user response time is spent getting the HTML document to the browser. You need to focus on the other 80-90% if you want to make your pages noticeably faster. These rules are the best practices for optimizing the way servers and browsers handle that 80-90% of the user experience.

These pages are the companion web site for the book High Performance Web Sites. The examples referenced in the book are hosted here. Navigate through the rules listed below to find the associated examples. Each rule page also contains a link to the Yahoo! Developer Network Performance Blog. There you will find a brief summary of the rule along with comments.


Rule 1 - Make Fewer HTTP Requests

Rule 2 - Use a Content Delivery Network

Rule 3 - Add an Expires Header

Rule 4 - Gzip Components

Rule 5 - Put Stylesheets at the Top

Rule 6 - Put Scripts at the Bottom

Rule 7 - Avoid CSS Expressions

Rule 8 - Make JavaScript and CSS External

Rule 9 - Reduce DNS Lookups

Rule 10 - Minify JavaScript

Rule 11 - Avoid Redirects

Rule 12 - Remove Duplicate Scripts

Rule 13 - Configure ETags

Rule 14 - Make AJAX Cacheable


来源：http://stevesouders.com/hpws/rules.php