Development

by Alexandru Plugaru

16 Add-ons in this Collection

Adblock Plus by Wladimir Palant

Rated 5 out of 5 stars 4,863 reviews

20,733,488 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 1,766 reviews

2,375,734 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...

FoxyProxy Standard by Eric H. Jung, groeg, others

Rated 4 out of 5 stars 334 reviews

323,166 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.
Collector's Note Must have

Web Developer by chrispederick

Rated 5 out of 5 stars 208 reviews

578,854 users

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

Tamper Data by Adam Judson

Rated 4 out of 5 stars 128 reviews

117,841 users

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

ColorZilla by Alex Sirota

Rated 5 out of 5 stars 300 reviews

261,777 users

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

MeasureIt by Kevin Freitas

Rated 4 out of 5 stars 328 reviews

151,606 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 186 reviews

110,756 users

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

SearchPreview by Edward Ackroyd

Rated 4 out of 5 stars 383 reviews

105,238 users

The extension previously known as GooglePreview. Inserts preview images (thumbnails) and popularity ranks of web sites into the Google, Yahoo, Bing and DuckDuckGo search results pages.

Html Validator by Marc Gueury

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

For Firefox 23+, you need 0.958 (under review)
http://users.skynet.be/mgueury/mozilla

FirePHP by cadorn

Rated 4 out of 5 stars 45 reviews

56,771 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 http://firephp.org/

Firefinder for Firebug by Robert Nyman

Rated 3 out of 5 stars 28 reviews

24,061 users

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

Firecookie by Jan Odvarko

Rated 4 out of 5 stars 61 reviews

4,836 users

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

Gmail Notifier by Doron Rosenberg

Rated 4 out of 5 stars 622 reviews

27,825 users

Note from Mozilla: This add-on has been discontinued. Try WebMail Notifier instead.

The original notifier for Gmail.

Source Viewer Tab by Piro (piro_or)

Rated 4 out of 5 stars 30 reviews

2,148 users

Shows web page sources in tab.
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