Why is the site so slow? Ryan Holder

There is a nice tool out there that builds on the firebug plug-in to help diagnose slow web pages. It is called YSlow and it is available on Yahoo. This tool gives a report card on various aspects of the web page under scrutiny. Aspects such as the number of http requests, duplicate JavaScript, weather or not the JavaScript on the page is minimized and gzipped, css analysis, number of domain names used on the page (each requires a dns lookup), etc. Here is the list of items it scores:

• Make fewer HTTP requests
• Use a CDN
• Add an Expires header
• Gzip components
• Put CSS at the top
• Put JS at the bottom
• Avoid CSS expressions
• Make JS and CSS external
• Reduce DNS lookups
• Minify JS
• Avoid redirects
• Remove duplicate scripts
• Configure ETags

Firebug also gives you the load time for each external resource:

• Posted In Engineering, QA, IT