Search Results for tag "developer"


Firebug integrates with Firefox to put a wealth of development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page...

Rated 4 out of 5 stars (2,587)
999,898 users

Web Developer Compatible with Firefox 57+

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

Rated 4 out of 5 stars (461)
292,525 users

Flagfox Compatible with Firefox 57+

Displays a country flag depicting the location of the current website's server and provides a multitude of tools such as site safety checks, whois, translation, similar sites, validation, URL shortening, and more...

Rated 5 out of 5 stars (825)
264,356 users

Clear Cache Compatible with Firefox 57+

Clear browser cache with a single click or via the F9 key.

F9 Fever! ;)

Rated 4 out of 5 stars (43)
24,822 users

Measure-it Compatible with Firefox 57+

Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.

Rated 5 out of 5 stars (28)
19,537 users

RESTED Compatible with Firefox 57+

A REST client for the rest of us

Rated 4 out of 5 stars (41)
23,100 users

HttpFox Requires Restart

An HTTP analyzer addon for Firefox

Rated 4 out of 5 stars (200)
44,607 users

Html Validator Compatible with Firefox 57+

HTML Validator is a Mozilla extension that adds HTML validation inside Firefox, Mozilla. The number of errors of a HTML page is seen on the form of an icon

For Firefox 56, use 0.974 (see all versions below).
For Firefox 57, see Web Extensions.

Rated 4 out of 5 stars (211)
34,528 users

Octotree Compatible with Firefox 57+

Add-on to display GitHub code in tree format

Rated 5 out of 5 stars (90)
8,135 users

Form Filler Compatible with Firefox 57+

This extension allows you to fill all form inputs (textboxes, textareas, radio buttons, dropdowns, etc.) with **random/dummy** data.

The purpose of this extension is to help developers test their forms quickly and easily.

Rated 5 out of 5 stars (18)
2,677 users

View Source Compatible with Firefox 57+

View Source button to easily open up View Source tab for the web page.

Rated 5 out of 5 stars (10)
7,875 users

YSlow Requires Restart

YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages. is the official open source website.

Rated 3 out of 5 stars (210)
28,893 users

JSONovich Compatible with Firefox 57+

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

Rated 4 out of 5 stars (47)
5,504 users

DOM Inspector Requires Restart

DOM Inspector is a tool that can be used to inspect and edit the live DOM of any web document or XUL application. The DOM can be navigated using a two-paned window displaying a variety of different views on the document and all nodes within.

Rated 5 out of 5 stars (78)
63,797 users

FirePHP Requires Restart

Log from PHP to a devtools panel.

Rated 4 out of 5 stars (58)
16,332 users

Fresh Dom Tree View Compatible with Firefox 57+

Web developers can inspect the DOM in a simple, intuitive way - like a pine tree!
On a web page, right-click and select Fresh Dom Tree View. Then explore: click within the generated dom tree, or mouse-over within the web page.

Rated 5 out of 5 stars (1)
352 users

Developer Tools - toolbar button Requires Restart

Access and activate the native Firefox Web Developer tools faster through this toolbar button (menu). Button can be placed on any toolbar.

Rated 5 out of 5 stars (10)
6,886 users

Display Page Resolution Compatible with Firefox 57+

Displays the page's current resolution in a tidy box at the top right.
Requires zero permissions and completely open source.

Rated 5 out of 5 stars (1)
261 users

Advanced GitHub Notifier Compatible with Firefox 57+

Shows notifications when you get a new notification on GitHub and provides quick access to all notifications in a popup.

Rated 5 out of 5 stars (6)
242 users

Firecookie Requires Restart

Firecookie is an extension for Firebug that makes possible to view and manage cookies in your browser

Firecookie is part of Firebug since Firebug 1.10

Rated 4 out of 5 stars (57)
1,123 users