Pro Developer

by JamesWilson

37 Add-ons in this Collection

Adblock Plus by Wladimir Palant

Rated 5 out of 5 stars 4,987 reviews

21,495,031 users

Blocks annoying video ads on YouTube, Facebook ads, banners and much more.

Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).

Firebug by Joe Hewitt, Jan Odvarko, others

Rated 5 out of 5 stars 1,799 reviews

2,256,333 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...

Greasemonkey by Anthony Lieuallen, Aaron Boodman, others

Rated 4 out of 5 stars 964 reviews

1,269,077 users

Customize the way a web page displays or behaves, by using small bits of JavaScript.

DownThemAll! by Nils Maier, Federico Parodi, others

Rated 5 out of 5 stars 1,625 reviews

1,354,593 users

The first and only download manager/accelerator built inside Firefox!

FoxyProxy Standard by Eric H. Jung, groeg, others

Rated 4 out of 5 stars 346 reviews

297,197 users

FoxyProxy is an advanced proxy management tool that completely replaces Firefox's limited proxying capabilities. For a simpler tool and less advanced configuration options, please use FoxyProxy Basic.

Web Developer by chrispederick

Rated 5 out of 5 stars 218 reviews

537,789 users

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

Full Web Page Screenshots (♥♥♥♥♥) by susbox

Rated 5 out of 5 stars 439 reviews

265,641 users

FireShot makes full web page screenshots. Demo:

Screenshots can be quickly captured and:

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

* OS Windows only

Tamper Data by Adam Judson

Rated 4 out of 5 stars 133 reviews

113,049 users

Use tamperdata to view and modify HTTP/HTTPS headers and post parameters...

JavaScript Debugger by James Ross, Robert Ginda, others

Rated 4 out of 5 stars 50 reviews

129,653 users

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.

ReloadEvery by Jaap Haitsma

Rated 4 out of 5 stars 677 reviews

167,157 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

286,986 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

164,090 users

View HTTP headers of a page and while browsing.

ColorfulTabs by Shivanand Sharma

Rated 4 out of 5 stars 995 reviews

223,693 users

The most beautiful yet the simplest add-on that makes a strong colorful appeal. Colors every tab in a different color and makes them easy to distinguish while beautifying the overall appearance of the interface. For Seamonkey & Flock. An essential. F...

MeasureIt by Kevin Freitas

Rated 4 out of 5 stars 341 reviews

148,513 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

95,993 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.
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