Pro Developer

by JamesWilson

37 Add-ons in this Collection

Adblock Plus by Wladimir Palant

Rated 5 out of 5 stars 4,965 reviews

21,124,276 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 1,790 reviews

2,307,758 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 956 reviews

1,265,766 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 1,609 reviews

1,366,130 users

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

ColorZilla by Alex Sirota

Rated 5 out of 5 stars 305 reviews

290,369 users

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

Web Developer by chrispederick

Rated 5 out of 5 stars 217 reviews

559,724 users

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

FoxyProxy Standard by Eric H. Jung, groeg, others

Rated 4 out of 5 stars 342 reviews

296,979 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.

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

Rated 5 out of 5 stars 433 reviews

267,280 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

MeasureIt by Kevin Freitas

Rated 4 out of 5 stars 337 reviews

151,062 users

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

Tamper Data by Adam Judson

Rated 4 out of 5 stars 132 reviews

114,713 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

135,086 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 676 reviews

170,159 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)

Live HTTP Headers by Daniel Savard, Nikolas Co

Rated 4 out of 5 stars 157 reviews

170,677 users

View HTTP headers of a page and while browsing.

ColorfulTabs by Shivanand Sharma

Rated 4 out of 5 stars 991 reviews

226,666 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...

YSlow by YSlow

Rated 3 out of 5 stars 195 reviews

101,599 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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