VirtualMV/Web Development/Building Web Site/Performance tuning/Content

Web Performance Best Practices and Rules
Yahoo!’s Exceptional Performance team identified 34 rules that affect web page performance. YSlow’s web page analysis is based on the 23 of these 34 rules that are testable. Click each performance rule below to see the details. (http://yslow.org/ )


 * 1) Minimize HTTP Requests
 * 2) Use a Content Delivery Network (Duplicates page assets (media) across servers in different geographical locations)
 * 3) Avoid empty src or href
 * 4) Add an Expires or a Cache-Control Header
 * 5) Gzip Components
 * 6) Put StyleSheets at the Top
 * 7) Put Scripts at the Bottom
 * 8) Avoid CSS Expressions
 * 9) Make JavaScript and CSS External
 * 10) Reduce DNS Lookups
 * 11) Minify JavaScript and CSS
 * 12) Avoid Redirects
 * 13) Remove Duplicate Scripts
 * 14) Configure ETags
 * 15) Make AJAX Cacheable
 * 16) Use GET for AJAX Requests
 * 17) Reduce the Number of DOM Elements
 * 18) No 404s
 * 19) Reduce Cookie Size
 * 20) Use Cookie-Free Domains for Components
 * 21) Avoid Filters
 * 22) Do Not Scale Images in HTML
 * 23) Make favicon.ico Small and Cacheable

You can test for each by adding the YSlow plug-in to your web browser. (http://yslow.org/ )