To use these add-ons, you'll need to download Firefox.

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Swift Selection Search

Simplify search by highlighting text on any web page to search the phrase from an array of engines.
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Extensions are like apps for Firefox.

They add features to Firefox to make browsing faster, safer, or just plain fun.
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Privacy & Security extensions
Privacy & Security extensions
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Tab managers
Tab managers
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The joy of creating themes
The joy of creating themes
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Extension starter pack
  • Privacy Badger

    Privacy Badger

    Automatically learns to block invisible trackers.

    1,546,640 users

  • Enhancer for YouTube™

    Enhancer for YouTube™

    Take control of YouTube and boost your user experience!

    669,866 users

  • Grammar and Spell Checker - LanguageTool

    Grammar and Spell Checker - LanguageTool

    With this extension you can check text with the free style and grammar checker LanguageTool. It finds many errors that a simple spell checker cannot detect, like mixing up there/their, a/an, or repeating a word.

    396,331 users

  • Search by Image

    Search by Image

    A powerful reverse image search tool, with support for various search engines, such as Google, Bing, Yandex, Baidu and TinEye.

    377,818 users

Creativity extensions
  • LeechBlock NG

    LeechBlock NG

    LeechBlock NG is a simple productivity tool designed to block those time-wasting sites that can suck the life out of your working day. All you need to do is specify which sites to block and when to block them.

    87,076 users

  • Grammar and Spell Checker - LanguageTool

    Grammar and Spell Checker - LanguageTool

    With this extension you can check text with the free style and grammar checker LanguageTool. It finds many errors that a simple spell checker cannot detect, like mixing up there/their, a/an, or repeating a word.

    396,331 users

  • Search by Image

    Search by Image

    A powerful reverse image search tool, with support for various search engines, such as Google, Bing, Yandex, Baidu and TinEye.

    377,818 users

  • Dictionary Anywhere

    Dictionary Anywhere

    View definitions easily as you browse the web. Double-click any word to view its definition in a small pop-up bubble. It also supports Spanish, German, French language alongside English. Enjoy Reading Uninterrupted!!!.

    45,629 users

Steam enhancers
  • SteamDB

    SteamDB

    Adds SteamDB links and new features on the Steam store and community. View lowest game prices and stats.

    61,594 users

  • Augmented Steam

    Augmented Steam

    Augments your Steam Experience

    59,668 users

  • Steam URL Opener

    Steam URL Opener

    Allows you to open URLs inside Steam Client to save the hassle of logging in normal browser (with a single click on a button).

    5,357 users

  • ProtonDB for Steam

    ProtonDB for Steam

    Shows ratings from protondb.com on Steam

    3,417 users

“video downloader” tagged extensions
  • Video DownloadHelper

    Video DownloadHelper

    Download videos from the web. Easy, smart, no tracking.

    1,983,803 users

  • Easy Youtube Video Downloader Express

    Easy Youtube Video Downloader Express

    A simple extension for superfast and easy YouTube downloads in FLV, 3GP, MP3, MP4, 720p, and 1080p formats.

    543,727 users

  • Download Video and Flash - HD Download

    Download Video and Flash - HD Download

    Download Video and Flash - HD Download is a great download helper tool that lets you download video and Flash games very easily. Download from YouTube, Facebook, Dailymotion, Vimeo and more. Download and enjoy! Download now!

    65,944 users

  • YouTube mp3

    YouTube mp3

    The YouTube-mp3 Add-on generates a "MP3" button on YouTube. Convert YouTube to mp3 and download the file to your device.

    36,056 users