Tools for Firefox and Chrome

Build for standards.

• Chrome includes a powerful set of development tools out of the box, including remote debugging.
• Firebug integrates with Firefox to put a wealth of development tools at your fingertips while you browse.
• HTML Validator is a Mozilla extension that adds HTML validation inside Firefox and Mozilla.
• Web Developer adds a menu and a toolbar with various web developer tools.
• IE Tab, an extension from Taiwan, embeds Internet Explorer in a Mozilla/Firefox tab. Handy but doesn’t work on a Mac.
• ColorZilla provides Advanced Eyedropper, Color Picker, Palette Viewer and other colorful goodies for your Firefox.
• YSlow analyzes web pages and tells you why they’re slow.
• HttpFox monitors and analyzes all incoming and outgoing HTTP traffic between the browser and the web servers.
• MultiFirefox is a small launcher utility that allows you to run multiple versions of Firefox side-by-side (Mac only).
• User Agent Switcher to spoof user agent strings for browser support testing.
• Fangs renders a text version of a web page similar to how a screen reader would read it.
• Google Toolbar to visualize Page Rank.

Tools for Internet Explorer

Ensure application compatibility.

• Internet Explorer Developer Toolbar provides a variety of tools for quickly creating, understanding, and troubleshooting Web pages. It also allows for the inspection of the MSIE-specific CSS passed in through the use of Conditional Comments.
• A look-alike is just that, not the real thing. Here are the Internet Explorer Application Compatibility VPC Images, made available by Microsoft for use in testing browser compatibility with MSIE.
• HttpWatch is a tool for monitoring HTTP traffic in IE.

Performance & Testing

Polish it to a bright shine.

• JSLint helps in checking how bad your script sucks. Just copy/paste and pray.
• WebPagetest will help access how slow your site is once it’s built.
• Validator.nu (X)HTML5 Validator validates HTML5.
• HTML5 outliner provides an easy to use document outline.
• Selenium IDE for automated testing, helping unlock the potential for test-driven development in the UI layer.
• Paros is a simplistic proxy tool that allows you to trap raw HTTP request and response headers for analysis and testing.