Dev Tools

by MattDMo

19 Add-ons in this Collection

Firebug by Joe Hewitt, Jan Odvarko, others

Rated 4 out of 5 stars 2,082 reviews

1,558,203 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...

User Agent Switcher by chrispederick

Rated 4 out of 5 stars 275 reviews

280,209 users

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

Web Developer by chrispederick

Rated 5 out of 5 stars 265 reviews

349,532 users

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

MeasureIt by Kevin Freitas

Rated 4 out of 5 stars 362 reviews

106,829 users

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

FireQuery by BinaryAge, Jan Odvarko

Rated 4 out of 5 stars 55 reviews

14,033 users

Firebug plugin for jQuery development

Execute JS by Rudolf Noe

Rated 5 out of 5 stars 15 reviews

4,059 users

Execute JS is a enhanced JavaScript-Console, where you can comfortably enter and execute arbitrary JavaScript-Code and modify functions...

Firepicker by thedarkone2

Rated 5 out of 5 stars 58 reviews

9,883 users

Simple color picker plugin for Firebug.

View Source Chart by Jennifer Madden

Rated 5 out of 5 stars 109 reviews

8,464 users

Enables accelerated human processing of DOM

Pencil by Dương Thành An, Brainiac

Rated 4 out of 5 stars 89 reviews

420 users

Pencil is a Firefox add-on to do GUI prototyping and simple sketching

Illuminations for Developers for Firebug by Steven Roussey

Rated 3 out of 5 stars 8 reviews

7,978 users

Enhances Firebug to understand JavaScript libraries and frameworks, making things more obvious and helpful when debugging. Trial version, fully functional.

Firefocus by kpdecker

Rated 4 out of 5 stars 3 reviews

435 users

Track Page Focus in Firebug

Firediff by kpdecker

Rated 4 out of 5 stars 16 reviews

6,654 users

Track Changes in Firebug

CSSsir by Razum

Rated 5 out of 5 stars 19 reviews

1,514 users

CSSsir is easy and handy tool which allows you to generate cross-browser code for main CSS- rules in a few clicks.
This CSS3 generator will be useful not only for web-masters and designers but also for common users.

FireFlow by sans_sense

Rated 4 out of 5 stars 4 reviews

473 users

Firebug extension to help reverse engineer code flows, does not work with Firefox version 33.0 and Firebug 2.0.4 and above.

FireFontFamily by Heather Arthur

Rated 4 out of 5 stars 13 reviews

823 users

Highlight the rendered font-family in Firebug
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