What resetting Firefox actually does

Resetting Firefox returns your browser to the state it was in when you first installed it. This means your homepage, search engine, extensions, and toolbar layout all go back to Firefox's original setup. Your bookmarks, passwords, and browsing history stay intact — reset only touches settings and add-ons, not your saved data.

Most people reset Firefox when the browser has become slow, crashes often, or behaves strangely. A reset clears out problematic extensions, corrupted settings, and accumulated cache that can gum up performance. It is faster and simpler than uninstalling and reinstalling Firefox from scratch, because you keep your bookmarks and login information.

The reset is reversible for 15 days — Firefox backs up your old settings in a folder on your computer, so you can restore them if you change your mind.

Key Takeaways

  • Resetting Firefox removes all extensions and returns settings to default, but keeps your bookmarks, passwords, and history.
  • You can restore your old settings within 15 days if the reset causes problems.
  • The reset button is in Firefox's troubleshooting page, which you reach through the Help menu.
  • Close all Firefox windows before you reset, or the reset may not complete.

How to find and use the reset button

Open Firefox and click the menu button — three horizontal lines in the top right corner. Select Help, then click More Troubleshooting Information. This opens the troubleshooting page.

Scroll down until you see the section labeled Give Firefox a tune up. Click the button that says Refresh Firefox. A dialog box will appear asking you to confirm. Click Refresh Firefox again.

Firefox will close automatically, reset itself, and reopen. The whole process takes less than a minute. When it reopens, your homepage will be back to the Firefox default, your extensions will be gone, and your search engine will be set to the default (usually Google).

What to do before you reset

Close all Firefox windows completely before you start the reset. If Firefox is running in the background or you have multiple windows open, the reset may fail or not take effect properly. Check your taskbar or system tray to make sure no Firefox processes are still running.

Write down any extensions you want to keep. When Firefox resets, all add-ons are removed. If you had extensions that you actually use — like a password manager, ad blocker, or grammar checker — you will need to reinstall them from the Firefox Add-ons page after the reset is complete. Making a list beforehand saves you time hunting for them later.

If you use Firefox Sync to keep your bookmarks and passwords synced across devices, make sure you are signed into your Firefox account before you reset. Sync will restore your bookmarks and passwords on this device after the reset finishes.

What happens to your data after reset

Your bookmarks, saved passwords, browsing history, and autofill information all remain on your computer. Firefox stores these separately from settings and extensions, so a reset does not touch them. When Firefox reopens after the reset, you can access all your bookmarks in the same places you left them.

If you use Firefox Sync, your bookmarks and passwords will sync back to this device within a few minutes of the reset. If you do not use Sync, your data stays local on your computer and is not affected by the reset at all.

Your cached files — temporary copies of web pages and images that Firefox stores to load sites faster — are cleared during the reset. This frees up disk space and can improve performance, especially if your cache folder had grown very large.

How to restore your old settings if something goes wrong

Firefox keeps a backup of your old settings for 15 days after a reset. If the reset caused problems or you realize you want your old setup back, you can restore it. Open the troubleshooting page again (Help > More Troubleshooting Information) and look for the section labeled Give Firefox a tune up. Click the button that says Restore.

Firefox will close, restore your old settings and extensions, and reopen. Your bookmarks and history are not affected by the restore — only your settings and add-ons change back. After 15 days, the backup is deleted and you can no longer restore your old setup.

When reset does not fix the problem

If Firefox still crashes or runs slowly after a reset, the problem may be outside Firefox itself. Check whether your computer is low on disk space or memory — Firefox needs both to run smoothly. Open your system settings to see how much free space you have on your hard drive. If you have less than 10 percent free, that alone can slow down any program.

Try disabling hardware acceleration, which can cause crashes on some computers. Go to Firefox settings (the menu button, then Settings), scroll to the Performance section, and uncheck the box next to Use recommended performance settings. Then uncheck Use hardware acceleration.

If problems continue, try creating a new Firefox profile instead of resetting. A profile is a separate folder where Firefox stores all your settings and data. A new profile starts completely fresh, separate from your current one, so you can test whether the problem follows you to the new profile or stays with the old one. This is more advanced than a reset, but it can pinpoint whether the issue is with Firefox itself or with something in your current profile.

Frequently Asked Questions

Will I lose my passwords if I reset Firefox?

No. Firefox stores passwords separately from settings and extensions. A reset removes your add-ons and returns settings to default, but your saved passwords stay on your computer. When Firefox reopens after the reset, your passwords are still there and you can log into sites automatically as usual.

Can I reset Firefox without closing it first?

You can click the reset button while Firefox is open, but the reset may not complete properly. Firefox will ask you to close all windows before the reset takes effect. It is safer and faster to close Firefox completely before you start the reset process.

What if I reset Firefox by accident?

You have 15 days to restore your old settings. Go back to Help > More Troubleshooting Information and click the Restore button. Your extensions and settings will come back. After 15 days, the backup is deleted and you cannot restore the old setup.

Does reset remove viruses or malware?

A reset removes malicious extensions that may have been installed without your knowledge, but it does not scan your computer for viruses. If you think your computer has malware, run a full scan with your antivirus software or Windows Defender after you reset Firefox. A reset is a good first step, but it is not a complete security fix.

Why is Firefox still slow after I reset it?

If Firefox is still slow after a reset, check whether your computer itself is the bottleneck. Low disk space, low memory, or too many programs running at startup can slow down Firefox even after a fresh reset. Check your system storage and close unnecessary background programs. If the problem persists, try disabling hardware acceleration in Firefox settings.