My Favorite Add-ons

by Francisco Javier

12 Add-ons in this Collection

Firebug by Joe Hewitt, Jan Odvarko, others

Rated 4 out of 5 stars 2,256 reviews

579,921 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...

DownThemAll! by Nils Maier, Federico Parodi, others

Rated 4 out of 5 stars 1,882 reviews

923,510 users

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

Xmarks Sync by Xmarks Inc.

Rated 4 out of 5 stars 2,614 reviews

174,059 users

Xmarks is the #1 bookmarking and open tab add-on. Keep your bookmarks, and open tabs backed up and synchronized across computers and browsers. Mobile phones with Premium access. Utilize LastPass to sync passwords!

Web Developer by chrispederick

Rated 5 out of 5 stars 284 reviews

291,028 users

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

ColorZilla by Alex Sirota

Rated 4 out of 5 stars 387 reviews

169,086 users

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

Wiktionary and Google Translate by Zen

Rated 4 out of 5 stars 200 reviews

47,882 users

(former Google Dictionary and Google Translate)

In-line dictionary for any word you point to or double-click; whole page translation of any web page in another language.

X-notifier (for Gmail,Hotmail,Yahoo,AOL ...) by Byungwook Kang

Rated 4 out of 5 stars 1,743 reviews

45,353 users

Notifier for gmail, yahoo, hotmail, aol and more webmails.
X-notifier(aka WebMail Notifier) checks your webmail accounts and notifies the number of unread emails...
Supports : gmail, yahoo, hotmail, POP3/IMAP, facebook, twitter and more

Html Validator by Marc Gueury

Rated 4 out of 5 stars 207 reviews

30,325 users

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

Until Firefox 56, use 0.974 (other versions)
For Firefox 57, see Web Extensions below

PDF Download by Nitro PDF Software

Download Now

Experimental

Rated 2 out of 5 stars 663 reviews

25,884 users

Use PDF Download to do whatever you like with PDF files on the Web. Regain control and eliminate browser problems, view PDFs directly in Firefox as HTML, and use the all-new Web-to-PDF toolbar to save and share Web pages as high-quality PDF files.

Pencil by Dương Thành An, Brainiac

Rated 4 out of 5 stars 89 reviews

361 users

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

FireQuery by BinaryAge, Jan Odvarko

Rated 4 out of 5 stars 54 reviews

8,903 users

Firebug plugin for jQuery development

iReader by MhdHejazi

Download Now

Experimental

Rated 4 out of 5 stars 102 reviews

1,810 users

View news stories and other articles in a very easy to read, clutter-free, scrollable display.

What are Collections?

Collections are groups of related add-ons that anyone can create and share.

Explore Collections