Below is a listing of our top 10 favorite Firefox add-ons and extensions. These software modules can be added to Firefox to customize its behavior, improve its security, and enhance its overall look and feel. These add-ons are found through the Mozilla Firefox add-ons page or the links provided below.

Privacy Badger

Developed by the EFF (Electronic Frontier Foundation), Privacy Badger learns to identify and block invisible trackers used by websites that follow your activity on the Internet. Unlike ad-blockers or other privacy add-ons, it does not require special configuration or a predefined list of trackers. Instead, it uses an algorithm that identifies new tracking technologies and those that are well-known and blocks them all.

In 2018, Mozilla made a major update to Firefox called Firefox Quantum. Add-ons for earlier versions of Firefox (before version number 57.0) may no longer work with up-to-date versions of Firefox. Make sure to update to the newest version of Firefox because it contains important security updates. If your old add-ons no longer work with Firefox or have not been updated for Firefox Quantum, you should not try to find a way to use them. Instead, look for an up-to-date extension that performs a similar function, such as those listed below.

  • Get the Privacy Badger add-on for Firefox.
  • Visit the Privacy Badger official website.

uBlock Origin

Another good privacy tool is uBlock Origin. It’s a wide-spectrum blocker, so it blocks thousands of trackers and malware sites, in addition to advertisements. It uses filter lists that can be downloaded from various sources and installed to make your blocking more robust. And it’s open-source, so you can trust what it’s doing with your data.

  • Get the uBlock Origin add-on for Firefox.
  • View the uBlock Origin source code on GitHub.

BitWarden Password Manager

BitWarden is an open-source password manager that helps you remember all the passwords you use online, keeping them secure with a master password. The source code is available for anyone to view and audit, so you can be sure that nothing insecure or unexpected happens to the passwords you store.

  • Get the BitWarden add-on for Firefox.
  • View the BitWarden source code on GitHub.

AdBlock

Not to be confused with an unrelated add-on called “AdBlock Plus,” AdBlock blocks all advertisements from your web browsing and does not track your web activity. We recommend using AdBlock instead of AdBlock Plus, which has received criticism (as publicized in the New York Times) for accepting payments from advertisers to whitelist their advertisements. In other words, AdBlock Plus still shows you ads, but only from advertisers who have made a payment to them. For this reason, we recommend if you want to block ads in Firefox, you give the plain AdBlock a try.

  • Get the AdBlock add-on for Firefox.
  • Visit the AdBlock official website.

DuckDuckGo Privacy Essentials

Created by DuckDuckGo, DuckDuckGo Privacy Essentials provides you with tools to control precisely how strong your privacy is while you browse the web. When you visit a website, the add-on analyzes its tracking behavior and gives it a grade (A, B, C, F, etc.) based on how safe your private information is. It provides you with in-depth information about what information the website is trying to see and gives you the option of enabling or disabling privacy protection.

  • Get the DuckDuckGo Privacy add-on for Firefox.
  • Visit the DuckDuckGo Privacy official website.

Firefox Multi-Account Containers

Developed by Mozilla, the Firefox Multi-Account Containers add-on gives you the ability to use color-coded tabs, each of which uses separate login session information. So, you can log in to Gmail in one Container tab, then log into a separate Google account in another Container tab, for example. The search histories, Gmail messages, YouTube activity, Google Drive files, etc., will be kept separate. The associated cookies and cached files are stored separately on your local drive. Multi-Account Containers help keep sensitive login sessions, such as your employer or financial institution, separate from every other site you visit.

  • Get the Multi-Account Containers add-on for Firefox.
  • Please read our guide to using Firefox Container tabs.

Easy Youtube Video Downloader Express

There seem to be endless plug-ins and websites that promise to help you download YouTube videos. Many of them are scams or don’t work correctly or tell you that you can only download in low quality unless you buy the paid version. Of all the plug-ins we’ve tried recently, Easy Youtube Video Downloader Express is the only one that:

  • Worked the first time.
  • Didn’t ask to install a “companion app.”

When the add-on is installed, you see a “Download As” button on any YouTube video page, below the “Share” option. Click it to show the best available MP4 quality available for that video. Select the MP4 video option in the drop-down menu to save the MP4 video to your computer.

  • Get the Easy Youtube Video Downloader Express add-on for Firefox.

Momentum Dash

If you’d like something more interesting to look at when you create a new Firefox tab, the Momentum Dash add-on gives you something a little more “zen.” It provides a pleasant photograph, the current time and date, weather information, and a to-do list that you can customize.

If you’re comfortable using the command line, we highly recommend YouTube-dl, a command-line YouTube downloader. It’s worked consistently for many years, and it’s free. It’s open-source and vigilantly upgraded to keep up with changes to YouTube’s API. For more information, see our guide to using YouTube-dl.

  • Get the Momentum Dash add-on for Firefox.
  • Visit the Momentum Dash official website.

Tree Style Tabs

If you frequently have many tabs open, it can get overwhelming seeing them all squished together at the top of your browser window. Tree Style Tabs is an add-on that displays your tabs in a sidebar of your browser window, grouped as a tree. If you open a link in a new tab, the new tab is indented, creating a “branch” in the tab tree. Branches can be individually collapsed or expanded at any level, as you need them.

  • Get the Tree Style Tabs add-on for Firefox.
  • View the Tree Style Tabs source code on GitHub.

Tomato Clock

If you’re looking for a simple time-management helper, Tomato Clock is a timer that helps you work in regular intervals and take short breaks. Developed by Samuel Jun, the add-on is implementing the “Pomodoro technique,” created by Francesco Cirillo. The technique is named after a timer in Cirillo’s kitchen that looked like a tomato (the Italian word for “tomato” is “pomodoro”). The add-on is surprisingly helpful and unobtrusive.

  • Get the Tomato Clock add-on for Firefox.
  • Visit the Tomato Clock author’s official website.
  • How to add add-ons and extensions to your browser.
  • How to disable or remove browser add-ons and extensions.
  • Computer Hope’s top 10 tips.