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Live HTTP Headers (clone) No Restart

View HTTP headers of a page and while browsing.

This is an unofficial "Live HTTP headers" clone, mainly to fix the Replay feature!

Not yet rated
1,047 users

about:addons-memory 2016 No Restart

Adds a new page that shows add-on memory usage

Rated 5 out of 5 stars (12)
4,530 users

Cookie Exporter

Exports all cookies in IE manner.
Makes a Netscape standard cookies.txt file.
Very useful for WGET --load-cookies option.

Rated 5 out of 5 stars (13)
4,611 users

Remote XUL Manager No Restart

Manages the Remote XUL whitelist to allow websites and local files to load XUL content. For versions compatible with Firefox 41 and lower, see All Versions page below.

Rated 5 out of 5 stars (36)
80,768 users

Clear Cache and Data No Restart

Clears the browser cache and other selected storage.

Rated 5 out of 5 stars (2)
4,821 users

View Source

Shows all source files of a webpage.

Rated 4 out of 5 stars (6)
1,235 users

Add-ons Manager - Version Number No Restart

Restores version numbers for all installed add-ons inside Add-on Manager on Firefox, Thunderbird and Seamonkey.

Rated 5 out of 5 stars (17)
1,346 users

Live HTTP Headers (Fixed By Danyial.com)

View HTTP headers of a page and while browsing.
Live HTTP Header Fix By Danyial ITs Working On Firefox Again Fixed Reply Problem

Rated 4 out of 5 stars (6)
1,356 users

RequestPolicy Continued No Restart

Be in control of which cross-site requests are allowed. Improve the privacy of your browsing by not letting other sites know your browsing habits. Secure yourself from Cross-Site Request Forgery (CSRF) and other attacks.

Rated 4 out of 5 stars (4)
7,364 users

NoRedirect

NoRedirect lets the user take control of HTTP redirects. It can be used to interdict an ISP's DNS search redirection hijacks, preview/screen "shortened" URLs (e.g., TinyURL), stop the annoying redirection of "smart" error pages, etc.

Rated 4 out of 5 stars (49)
13,927 users

Dafizilla Table2Clipboard

Mozilla applications allow to select rows and columns from a table simply pressing Control key and picking rows/columns with left mouse button.
The selection can be copied to clipboard but the original table disposition is lost making ugly results wh...

Rated 5 out of 5 stars (63)
18,687 users

Full Web Page Screenshots (♥♥♥♥♥)

FireShot makes full web page screenshots. Demo: http://bit.ly/RlBQMV

Screenshots can be quickly captured and:

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

* OS Windows only

Rated 5 out of 5 stars (452)
279,529 users

JSONovich No Restart

Pretty-prints JSON content in the browser for easy, unobtrusive viewing.

Rated 4 out of 5 stars (34)
9,730 users

Element Inspector No Restart

In the DOM Inspector,quickly navigate to the any elements

Rated 5 out of 5 stars (27)
3,296 users

User Agent Switcher

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

Rated 4 out of 5 stars (262)
343,383 users

Font Finder

FontFinder is created for designers, developers and typographers. It allows a user to analyze the font information of any element on a page, copy any piece(s) of that information to the clipboard, and perform inline replacements to test new layouts.

Rated 4 out of 5 stars (69)
35,118 users

SQLite Manager

Manage any SQLite database on your computer.

Rated 5 out of 5 stars (47)
199,810 users

Live HTTP Headers

View HTTP headers of a page and while browsing.

Rated 4 out of 5 stars (168)
153,516 users

Link Properties Plus

Provides extended link properties: size of linked file, last modified time, etc.

Rated 5 out of 5 stars (13)
1,822 users

Firesizer

Allows you to resize the window to specific dimensions.

NOTE: Users of Firefox 29 and above must install "The Addon Bar" extension to use this, as Firesizer uses the add-on bar that has been removed in Firefox 29.

Rated 4 out of 5 stars (129)
27,144 users