Top 10 Firefox add-ons

Updated: 06/30/2019 by Computer Hope
Illustration: Firefox add-ons.

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. Each of these add-ons can be found through the Mozilla Firefox add-ons page, or through the links provided below.


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.

Privacy Badger

Logo: 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, as well as those that are well-known, and blocks them all.

uBlock Origin

Logo: 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.

BitWarden Password Manager

Logo: 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.


Logo: 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 it 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 that if you want to block ads in Firefox, you give the plain AdBlock a try.

DuckDuckGo Privacy Essentials

Logo: DuckDuckGo.

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 for that site.

Firefox Multi-Account Containers

Illustration: 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 are useful for keeping sensitive login sessions, such as your employer or financial institution, separate from every other site you visit.

YouTube MP4 Downloader

Logo: YouTube Video Downloader - HD Download.

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, YouTube MP4 Downloader is the only one that:

  1. Worked the first time.
  2. Didn't ask to install a "companion app," or try to upsell a paid version.

When the add-on is installed, you'll see a "Download" button on any YouTube video page, near the "Share" button. Click it to show the best available MP4 quality available for that video. Click the format name to view the video as an MP4 in your browser. Then, press Ctrl+S to save this MP4 video to your computer.

Screenshot: Using YouTube MP4 Download to download a YouTube video as a 720p MP4.


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.

Momentum Dash

Logo: Momentum Add-on for Firefox.

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.

Screenshot: Momentum Dash add-on for Firefox.

Tree Style Tabs

Screenshot: Tree Style Tabs add-on for Firefox.

If you frequently have a lot of 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.

Tomato Clock

Logo and screenshot: Tomato Clock add-on for Firefox.

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 an implementation of 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 useful and unobtrusive.

Screenshot: Pomodoro completa.