Web Performance Analysis & Optimization tools

 If you cannot measure it, you cannot improve it - Lord Kelvin

There are a bunch of free Web Performance Analysis & Optimization tools that web developers can take advantage of to build blazing fast web pages -

• Page Speed - open source Firebug plugin
• YSlow  - Firebug plugin from Yahoo
• AOL Pagetest - appears under the Tools menu in Internet Explorer after installation. Online version of Pagetest also provides Optimization Report.
• Zoompf -  this web-based service can detect over 300 possible issues & provide recommendations
• MSFast/MySpace’s Performance Tracker - IE browser plugin from MySpace
• VRTA  (Visual Round Trip Analyzer) - Microsoft tool that works along with Netmon
• neXpert - works with Fiddler. Especially useful for pages built with ASP.NET
• Web Page Analyzer - incorporates the latest best practices from the book Website Optimization
• Yottaa - measures performance, provides customized analytics & optimization tips 
• Torbit - provides realtime dashboard,  shows the loading times your visitors are experiencing right now and spot any performance issues that may be affecting a particular region. 

These tools provide suggestions that not just cut page download time but also operational costs. I learnt about some of these tools from web performance guru Steve Souders' blog

Also see:
HOW TO improve the front-end performance of a website

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