Firefox automatically updates itself by default but you can always do a manual update. Learn how to update Firefox on Windows, Mac or Linux.
Windows 10 may interrupt your Firefox install with a warning about "Microsoft-verified apps". Firefox is safe to install and use, so choose "install anyway".
The "Mozilla Firefox" app is available from the Microsoft Store for Windows 10 and Windows 11. Learn how to install it.
This article describes how to download and install Firefox on Linux.
This article describes how to download and install Firefox on Windows.
Firefox and Thunderbird install Mozilla Maintenance Service to allow seamless background updates. Learn how it works and how to disable or remove it.
What to do if you spot fake notices claiming to contain an "urgent" or "critical" Firefox update.
If your bookmarks, passwords, preference settings and other data are missing, it may be available in another Firefox profile. Learn more.
Downgrading to a previous Firefox version doesn't solve most problems. This article links to older versions and provides some alternatives.
This article explains how to download and install Firefox on a Mac.
Firefox version 52.9.0esr was the last supported release for Windows XP and Windows Vista. No further security updates will be provided for those systems.
This article describes how to remove the Firefox application from your computer and also how to remove the personal information that Firefox stores.
Learn how to find out what Firefox version you are using, to help troubleshoot a problem or just to know if Firefox is up to date.
Not sure whether you're running 32-bit or 64-bit Firefox on your Windows or Linux computer? This article explains how to find out.
How to switch to Firefox ESR as a workaround for issues with the newest version of Firefox.
You cannot install Firefox from Mozilla or from the Microsoft Store on Windows in S mode. You must first switch out of S mode. Learn more.
Firefox 78 was the last supported version for Mac OS X 10.9, 10.10 and 10.11. Users were moved to Firefox Extended Support Release (ESR).
On Windows 7 you need Microsoft update KB4474419 to install Firefox 100 and above. Learn if you have this Windows update and where to find out more.
Links to release notes for Firefox and Firefox for Android.