The Firefox extensions worth adding are the ones that do one everyday job well: blocking ads and trackers, dark mode, saving passwords, translating pages or grabbing screenshots. Each one installs from Mozilla Add-ons in a click. Ten follow, one per job, listed in no particular order with users, ratings and update dates as the store shows them.
Firefox extensions add the small jobs the browser doesn't do on its own, and the trick is choosing one per job rather than ten that overlap. Two blockers fighting over the same page won't make your browsing any calmer.
I've kept to one add-on for each everyday task, and every detail below comes from its Mozilla Add-ons listing as of Oct 2026. If a stream ever stalls on you, my guide to fixing Twitch not working on Firefox walks through the usual causes.
How I chose these Firefox add-ons, side by side
I worked from what each Mozilla Add-ons listing shows: the number of users, the rating and how many people left one, the last updated date, the publisher and whether Mozilla's recommended badge appears. Nothing here comes from my own speed or privacy checks. The free plan column says Yes only where the listing itself mentions free use; Not stated means it didn't say, which isn't the same as charging.
| Tool | Type | Good for | Free plan |
|---|---|---|---|
| Bitwarden Password Manager | Password manager | Passwords, passkeys and sensitive notes | Yes |
| Dark Reader | Dark mode | Dark themes on every website | Not stated |
| Easy Screenshot | Page capture tool | Full page captures saved to desktop | Not stated |
| Facebook Container | Tracking isolation | Keeping Facebook activity separate | Not stated |
| Grammarly | Writing assistant | Grammar and tone while you type | Not stated |
| Privacy Badger | Tracker blocker | Companies tracking you across sites | Not stated |
| Tampermonkey | Userscript manager | Running small scripts on websites | Not stated |
| TWP Translate Web Pages | Page translator | Translating pages without a new tab | Not stated |
| uBlock Origin | Content blocker | Ads, trackers and page clutter | Yes |
| Video Download Helper | Video saver | Saving videos you're allowed to keep | Not stated |
Ten Mozilla add-ons, one for each everyday job
Bitwarden Password Manager
Best for: Keeping passwords and passkeys in one vault, from Bitwarden Inc., whose listing says you can use it for free with no ads.
Dark Reader
Best for: Turning every website dark for night reading, from Dark Reader Ltd, with 1,352,609 users and an update dated Oct 28, 2026.
Easy Screenshot
Best for: Capturing a whole webpage as an image and saving it to your desktop, though its listing shows a last update of Dec 28, 2022.
Facebook Container
Best for: Keeping Facebook's tracking away from the rest of your browsing, from the publisher listed as Firefox, last updated Mar 10, 2025.
Grammarly
Best for: Grammar fixes and tone changes right where you write in Firefox, with AI drafting too, rated 4.1 by 3,227 people as of Oct 2026.
Privacy Badger
Best for: Stopping companies from following you around the web, from the digital rights nonprofit EFF, with Mozilla's recommended badge on its listing.
Tampermonkey
Best for: Running userscripts that change how sites look or behave, from developer Jan Biniok, for people happy to tinker a little.
TWP Translate Web Pages
Best for: Translating a whole page in place with Google, Bing or Yandex, without opening a new tab, from developer Filipe Dev.
uBlock Origin
Best for: Blocking ads and page clutter on every site, from a content blocker its listing calls easy on CPU and memory, with 11,365,567 users as of Oct 2026.
Video Download Helper
Best for: Saving videos from web pages you're allowed to keep, with a listing that promises no tracking and an update dated Oct 21, 2026.
Which kind of add-on for which job in Firefox
- Ads and clutter: a content blocker. One is enough; stacking two only gives you more settings to manage.
- Being followed by trackers: a tracker blocker from a privacy group, or a container that walls off one social network.
- Passwords: a password manager add-on tied to an account you can open on your phone as well.
- Late night reading: a dark mode add-on that themes every site, not just the ones that offer a dark setting.
- Reading in another language: a page translator that works in place, so you don't lose your tab.
- Changing how one site works: a userscript manager, as long as you only run scripts from sources you trust.
- Writing emails and posts in the browser: a writing assistant that checks grammar as you type.
If something here didn't fit your situation, the best Firefox password manager add-ons may.
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Reviews tell a different story from installs
Here's something the headline numbers hide. On Mozilla Add-ons the user count and the number of ratings move separately: Video Download Helper shows 42,803 ratings on 1,837,761 users, while Easy Screenshot shows 772 ratings on 1,273,726 users, as of Oct 2026.
So two add-ons with similar audiences can have very different amounts of feedback behind their stars. A big install count with few ratings tells you less than it seems, so check the last updated date too and read the newest reviews before you trust an add-on with your browsing. Mozilla's recommended badge shows on some listings and not others; it's a useful extra signal, and it's Mozilla's label, not mine.
For a closer look at the related setup, see the best Firefox ad blockers.
Keep your add-on shelf short
- Install one add-on per job and remove anything you haven't touched in a month.
- Check that the publisher on the listing is the company or developer you expect.
- Look at the last updated date, because a long gap usually means fewer fixes.
- Read what the add-on asks permission to do before you click Add to Firefox.
Do you make Firefox add-ons? Tool makers can ask to be considered for a featured place on this list.
My plain advice before you install anything
Start with the job you want done, then choose one add-on for it and live with it for a week. For most of us a blocker and a password manager are the sensible first two, and everything else can wait until you notice you need it.
If you write a lot in the browser, my roundup of grammar checkers covers more options than the one writing add-on here, and if you'd like a strong password in a second, my password generator makes one for you.
Want your tool on this list? Featured spots and reviews here are paid partnerships. Here's how to partner with me.
Frequently asked questions
What are the most useful Firefox extensions?
The ones that cover an everyday job: an ad or tracker blocker, a password manager, dark mode, a page translator and a screenshot tool. One add-on per job keeps things simple.
Are Firefox extensions safe to install?
Stick to listings on Mozilla Add-ons, check the publisher and the last updated date, and read what the add-on asks permission to do. Mozilla's recommended badge appears on some listings, which is one more thing to look for.
How many extensions should I run in Firefox?
As few as you need. Every add-on can see some of what you do in the browser, so keep the ones you use and remove the rest.
Why does an add-on with lots of users have so few ratings?
Leaving a rating is optional, so the number of ratings is always far smaller than the user count. That's why a big user number with a small pile of ratings tells you less than you'd think.
Can I use these Firefox extensions for free?
Some listings here mention free use in their own text and the rest don't say either way, as of Oct 2026. The free plan column shows which, so check each listing before you rely on it.
