Web and Developer Tools

Subscribe

Remote XUL Manager

Manages the Remote XUL whitelist to allow websites and local files to load XUL content. For versions compatible with Firefox 41 and lower, see All Versions page below.

Rated 5 out of 5 stars (37)
89,844 users

Image Zoom (ugly fixes) Requires Restart

An ugly attempt at fixing Image Zoom

Rated 4 out of 5 stars (10)
2,530 users

Proxy Tool Requires Restart

Proxy Tool - Powerful, yet User-friendly proxy tool to manage your proxies and anonymity needs, including: 46M+ user agents (world's largest), 10 different spoofed HTTP referrers, auto-proxy rotation, plus many more. Developed by http://ProxyList.co

Rated 4 out of 5 stars (40)
140,434 users

Copy Pure Text Requires Restart

Allows to copy selected text as plain text by adding a 'Copy as Text' menu item to context menu.

Rated 4 out of 5 stars (15)
5,774 users

JavaScript Debugger Requires Restart

As of Firefox 33, Venkman *no longer works*, as the APIs which it needs have been removed.

Venkman is the code name for Mozilla's JavaScript Debugger. Venkman aimed to provide a powerful JavaScript debugging environment for Mozilla based browsers.

Rated 4 out of 5 stars (50)
115,117 users

Tiny JavaScript Debugger Requires Restart

TinyJSD is a JavaScript debugger for privileged code running Mozilla products like Firefox, Thunderbird, SeaMonkey. It serves to debug the application as well as extensions written in JavaScript.

Rated 4 out of 5 stars (7)
35,130 users

jQuery Requires Restart

jQuery and jQuery UI embedded in browser

Rated 4 out of 5 stars (7)
2,701 users

Sharp Color Picker

A full featured color selector tool, to work with colors, and easily find the colors you want.

Rated 4 out of 5 stars (1)
2,379 users

JSONovich

Pretty-prints JSON content in the browser for easy, unobtrusive viewing.

Rated 4 out of 5 stars (38)
8,749 users

Live HTTP Headers (clone)

View HTTP headers of a page and while browsing.

This is an unofficial "Live HTTP headers" clone, mainly to fix the Replay feature!

Rated 4 out of 5 stars (7)
5,792 users

User Agent Switcher Requires Restart

The User Agent Switcher extension adds a menu and a toolbar button to switch the user agent of a browser.

Rated 4 out of 5 stars (273)
334,259 users

Full Web Page Screenshots (♥♥♥♥♥) Requires Restart

FireShot makes full web page screenshots. Demo: http://bit.ly/RlBQMV

Screenshots can be quickly captured and:

― Saved as Image or PDF
― Sent to clipboard
― Printed
― Annotated *
― Uploaded *
― E-Mailed *

* OS Windows only

Rated 5 out of 5 stars (493)
301,195 users

HttpFox Requires Restart

An HTTP analyzer addon for Firefox

Rated 4 out of 5 stars (172)
84,018 users

Web Developer Requires Restart

The Web Developer extension adds various web developer tools to the browser.

Rated 5 out of 5 stars (262)
460,936 users

Font Finder Requires Restart

FontFinder is created for designers, developers and typographers. It allows a user to analyze the font information of any element on a page, copy any piece(s) of that information to the clipboard, and perform inline replacements to test new layouts.

Rated 4 out of 5 stars (78)
37,385 users

Firesizer Requires Restart

Allows you to resize the window to specific dimensions.

NOTE: Users of Firefox 29 and above must install "The Addon Bar" extension to use this, as Firesizer uses the add-on bar that has been removed in Firefox 29.

Rated 4 out of 5 stars (132)
25,494 users

CloudBleed

CloudBleed, search have you visited affected websites recently by browser history.

Rated 5 out of 5 stars (3)
2,724 users

View Source Requires Restart

Shows all source files of a webpage.

Rated 4 out of 5 stars (6)
1,185 users

Element Inspector

In the DOM Inspector,quickly navigate to the any elements

Rated 5 out of 5 stars (32)
4,287 users

Screengrab (fix version) Requires Restart

Screengrab! saves webpages as images.
0.99 released!
New features: upload to internet

Rated 5 out of 5 stars (322)
133,725 users