Must-Have Web Dev Tools

by stuartherbert

29 Add-ons in this Collection

Firebug by Joe Hewitt, Jan Odvarko, others

Rated 5 out of 5 stars 1,799 reviews

2,140,257 users

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...

iMacros for Firefox by iMacros

Rated 4 out of 5 stars 381 reviews

376,490 users

Automate Firefox. Record and replay repetitious work. If you love the Firefox web browser, but are tired of repetitive tasks like visiting the same sites every days, filling out forms, and remembering passwords, then iMacros for Firefox is the soluti...

Web Developer by chrispederick

Rated 5 out of 5 stars 218 reviews

511,380 users

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

ReloadEvery by Jaap Haitsma

Rated 4 out of 5 stars 677 reviews

163,504 users

Reloads web pages every so many seconds or minutes. The function is accessible via the context menu (menu you get when you right click on a web page) or via tab context menu (right click on the tab)

ColorZilla by Alex Sirota

Rated 5 out of 5 stars 306 reviews

273,170 users

Advanced Eyedropper, Color Picker, Gradient Generator and other colorful goodies...

Live HTTP Headers by Daniel Savard, Nikolas Co

Rated 4 out of 5 stars 159 reviews

156,390 users

View HTTP headers of a page and while browsing.

JSONView by Ben Hollis

Rated 5 out of 5 stars 134 reviews

97,122 users

View JSON documents in the browser.

MeasureIt by Kevin Freitas

Rated 4 out of 5 stars 341 reviews

140,140 users

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

YSlow by YSlow

Rated 3 out of 5 stars 199 reviews

90,862 users

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.

Selenium IDE by Jason Huggins, Adam Goucher, others

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Rated 5 out of 5 stars 1 review

5,013 users

Selenium IDE is an integrated development environment for Selenium tests. It is implemented as a Firefox extension, and allows you to record, edit, and debug tests.

FirePHP by cadorn

Rated 4 out of 5 stars 47 reviews

47,057 users

FirePHP enables you to log to your Firebug Console using a simple PHP method call.

Not using Firebug 1.9+ on Firefox 8+? See

Abduction! - Webpage Screenshots Screen Capture by M. Evans

Rated 4 out of 5 stars 519 reviews

40,799 users

1) Capture an page or just a specific region.
2) Adds a right click option to take screen shots of an entire web page or just part of a web page to save as an image.


Firesizer by orev

Rated 4 out of 5 stars 127 reviews

27,170 users

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.

Firefinder for Firebug by Robert Nyman

Rated 3 out of 5 stars 28 reviews

21,151 users

Finds HTML elements matching chosen CSS selector(s) or XPath expression

Dust-Me Selectors by brothercake

Rated 4 out of 5 stars 79 reviews

15,230 users

Dust-Me Selectors is development tool to remove unused CSS selectors.
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