Twenty new rules have been added to the original 14 rules for sizzling web performance. Part of scalability is worrying about performance too. The front-end is where 80-90% of end-user response time is spent and following these best practices improved the performance of Yahoo! properties by 25-50%. The rules are divided into server, content, cookie, JavaScript, CSS, images, and mobile categories. The new rules are:

Twenty new rules have been added to the original 14 rules for sizzling web performance. Part of scalability is worrying about performance too. The front-end is where 80-90% of end-user response time is spent and following these best practices improved the performance of Yahoo! properties by 25-50%. The rules are divided into server, content, cookie, JavaScript, CSS, images, and mobile categories. The new rules are:

# Flush the buffer early [server]
# Use GET for AJAX requests [server]
# Post-load components [content]
# Preload components [content]
# Reduce the number of DOM elements [content]
# Split components across domains [content]
# Minimize the number of iframes [content]
# No 404s [content]
# Reduce cookie size [cookie]
# Use cookie-free domains for components [cookie]
# Minimize DOM access [javascript]
# Develop smart event handlers [javascript]
# Choose

over @import [css]
# Avoid filters [css]
# Optimize images [images]
# Optimize CSS sprites [images]
# Don’t scale images in HTML [images]
# Make favicon.ico small and cacheable [images]
# Keep components under 25K [mobile]
# Pack components into a multipart document [mobile]