Every day there are numerous new extensions being implemented by Firefox. Despite the fact some of them will be useful for web development and some not, we try to install extensions for web development purpose. But finally, we might not need them. Firefox extensions for web developers, which can be of great help or might end up with less help to them. On analyzing a few hundreds of extensions, we have chosen best ten on the daily usage basis, which might be most useful Firefox extensions to the web developers. We have been struck by many FireFox extensions, but these are the ones we use daily.

Here’s a list of 10 useful FireFox extensions that all web developers should know about

Web Developer

This Firefox extension allows the user to disable, view, and edit cookies, CSS, HTML, forms, and images; validate pages; and much more. The tool adds a menu and a toolbar, with a great collection of web developer tools to the browsers.


DOM Inspector

This Firefox extension analyzes and edits live DOM for any web page or XUL applications. This extension is very useful for testing and debugging CSS.


XML Developer Toolbar

This Firefox extension toolbar allows XML developer’s use for all browser and has many features like Schema Generation, DTD Generation, Schema Validation, XML -> Schema Validation, Style Manipulation, XSL Transformations on-the-fly, DOM Inspector incorporated views, Document statistics for future Semantic Web purposes.



This Firefox extension tool monitors JavaScript, CSS, HTML, and Ajax, and they are in one including a debugger, an error console, command line. Features includes JavaScript debugger for stepping through code one line at a time, Status bar icon shows you when there is an error in a web page, a console that shows errors from JavaScript and CSS, Log messages from JavaScript in your web page to the console (bye bye “alert debugging”), An JavaScript command line (no more “javascript:” in the URL bar), Spy on XMLHttpRequest traffic, Inspect HTML source, computed style, events, layout and the DOM.



This Firefox tool extension allows easy management of user style. This toolbar can be used for fixing ugly sites.


Server Switcher

This Firefox extension is a navigational help tool for web developers and allows switching between sites on your development and live servers; it helps you to see the difference immediately.

When you are on http://localhost/test.html (your development server) and click the Server Switcher icon you will instantly be redirected to http://www.yoursite.com/ test.html (your live server). (“localhost” and “www.yoursite.com” are of course configurable).Features includes  create multiple development/live-server-pairs, Open local/remote server in a new tab with middle click or CTRL+leftclick, Support for ports (e.g. localhost:81), support for subdirectories (e.g. localhost/sitename), support for HTTPS (e.g. https://www.yoursite.com), support for local files (e.g. file:///D:/www), works in Firefox and Flock.


Tamper Data

These Firefox extensions to view and modify HTTP/HTTPS headers and post parameters and can be used to trace and time http response/request.


Total Validator

This tool can be used to perform multiple validations like HTML validation, accessibility validation, check for broken links, perform spell check (5 languages) and take screen shots in one go rather than using separate tools. This tool can do security test for web applications by modifying POST parameters. This tool works on the external, internal, or local web for different browsers on different platforms like Windows, Linux, OS/X and more.