Modify Header Value
Add, modify or remove a header for any request on desired domains.
10,545 users
HackBar
A HackBar for new firefox (Firefox Quantum). This addon is written in webextension and alternatives to the XUL version of original Hackbar. Press F12 to use HackBar
10,149 users
Emoji Keyboard - Emojis For Firefox
A free extension of the web tool https://coolsymbol.com/emojis/emoji-for-copy-and-paste.html. It helps input emoji in the web browser with an extensive search functionality.
9,799 users
Html Validator
HTML Validator is a Mozilla extension that adds HTML validation inside Firefox, Mozilla. The number of errors of a HTML page is seen on the form of an icon For Firefox 56, use 0.974 (see all versions below). For Firefox 57, see Web Extensions.
9,673 users
WhatRuns
Discover what runs a website - This Firefox extension helps you identify technologies used on any website at the click of a button.
9,492 users
EditThisCookie
EditThisCookie is a cookie manager.
9,367 users
Mobile simulator
Smartphone simulator on computer very realistic with several models to test mobile websites.
9,003 users
BuiltWith
BuiltWith is a web site profiler tool. Upon looking up a page, BuiltWith returns a list all the technologies in use on that page that it can find.
8,930 users
daily.dev | The homepage developers deserve
Get one personalized feed for all the knowledge you need as a developer.
8,842 users
Ignore X-Frame-Options Header
Allows all sites to be loaded in iframes, despite X-Frame-Options header settings.
8,825 users
Refined GitHub
Simplifies the GitHub interface and adds many useful features.
8,785 users
axe DevTools® - Web Accessibility Testing
Add accessibility auditing to the Firefox Developer Tools
8,714 users
Page Saver WE screenshot capture tool
Quickly and easily capture an image of a web page. Options allow you to control output format (PNG or JPEG), file name and more.
8,446 users
ruler
Simple tool for measuring arbitrary parts of a page. Does not and will never contain adware.
8,274 users
Purple Ads BlockerPurple Ads Blocker
Purple AdBlock is a adblock for Twitch.tv
8,096 users
Apollo Client Devtools
GraphQL debugging tools for Apollo Client.
8,077 users
Form History Control
Manage form history entries (search, edit, cleanup, export/import) and easy text formfiller. Auto-save text entered in any form while typing to allow fast recovery when disaster strikes.
8,021 users
Export Cookies
Export cookies to a Netscape format cookies.txt file.
7,795 users
JetBrains Toolbox Extension
Clone and open projects from GitHub, GitLab, and Bitbucket in JetBrains IDEs right from your browser
7,793 users
All Downloader Professional
All Downloader Professional finds links, images, videos, documents on a website an make them downloadable.
7,665 users
Save Screenshot
Saves the current page as image file or copies it to clipboard.
7,528 users
WebScrapBook
Capture web pages to local device or backend server for future retrieval, organization, annotation, and edit.
7,364 users
JavaScript Switcher
A lightweight addon that adds a Toggle button in URL bar, for toggling JavaScript (on or off) individually per domain, and stores that for future visit. Works also with Firefox 57+.
7,215 users
Cookie Remover
Removes cookies for the current site
7,151 users
EditThisCookie2
EditThisCookie is a cookie manager. You can add, delete, edit, search, protect and block cookies!
7,083 users