Firebug is one of the best tools, is used by website developers in a large volume for providing better compatibility with JavaScript & Ajax. As fire fox add on, it has a great number of features that makes it out of box tool; it can easily works within browser and don’t need to switch between applications, it logs to every request, it can edit code and provides results, instantly and above all, it can debug JavaScript.

Following are some Firefox add-ons to provide more vitality to Firebug:

YSlow: This is a Firebug add-on to help in analyzing and providing ideas for web-pages in comparison to high performing web pages. YSlow grading system for web pages is a defined rule sets or customized one. It provides tools for performance analysis like Smush.it™ and JSLint.

Page Speed: This tool on the same lines of YSlow is an add-on by the Google team to compare performances of web pages and retain ideas to improve them. Page Speed featured to optimizes images and compress them for uploading.

Pixel Perfect: This is very handy tool to learn about, how a fresh element would look like on a design, it allows web developers and designers to overlay a web composition on a developed HTML to toggle on/off any number of design elements to look out whether, how they looks out to be there.

CodeBurner: This is a reference panel that helps to look out for HTML elements, attributes, and CSS properties. It is also featured to provide a designer with shortcuts to look out for information or code samples for a selected item.

FireUnit: This is a simple JavaScript API allows simple test logging - unit testing within a new tab of Firebug.

FirePHP: FirePHP let to log on to Firebug console by a simple PHP method call.    In the process, Data is provided through headers & won’t interfere with the content on the page. It is a great help for PHP debugging.

FireRainbow: FireRainbow helps for a better syntax presentation support to Firebug.

FireDiff: It monitors every change made to CSS and DOM by Firebug and the website itself. It can look deeper into the functionality of the website and can maintain changes.

Jiffy Firefox Extension: Jiffy Extension employing Jiffy-Web appends a new panel to Firebug and lets visual view of the JavaScript time measurements.

Hammerhead: With support for multiple pages it can clear caches (disk & memory) and helps in measuring the loading of the web pages.

Firecookie: Firecookie, a cookie viewer/manager helps for a faster development within the site in a coding, where, applications uses cookies.

LiveCoder: LiveCoder is helpful for developers, who develop add-ons while providing access to Firefox chrome.