Firefox Keeps Crashing or Quitting Unexpectedly? Here's the Fix

Q: What is a crash Report ID?

After a crash, type about:crashes to see submitted reports. The Report ID helps Mozilla support diagnose a crash that survives Troubleshoot Mode.

Published ✓ Verified ⏱️ 2 min read July 18, 2025 · by Ryan Bennett

Firefox closes by itself, shows a crash reporter, or quits the moment you open it.

Why: Most repeat crashes come from an extension, a theme, or hardware acceleration fighting with your graphics driver. Startup crashes can also be an outdated build or a damaged profile. Test in a clean mode to tell which it is, then fix only that.

Fix 1: Update Firefox

Open menu (≡) → Help → About Firefox.
Firefox checks for and downloads any update; click Restart to update Firefox.

Every release fixes known crashes, so this alone often resolves it. While you are at it, update Windows and your graphics driver — both are common crash sources.

Fix 2: Test in Troubleshoot Mode (isolate the cause)

Open menu (≡) → Help → Troubleshoot Mode… and click Restart.
Confirm with Open. Firefox restarts with all extensions, themes, and hardware acceleration disabled.
Use it normally for a while.

No more crashes? An add-on or hardware acceleration was the cause. Go to about:addons, disable add-ons, and re-enable them one at a time to find the bad one. To rule out the GPU, turn off hardware acceleration in Settings → General → Performance (untick Use recommended performance settings, then untick Use hardware acceleration when available).
Still crashing? The cause is not an extension — move to Fix 3. Antivirus and other tools sometimes inject modules that crash Firefox, so check those too.

Fix 3: Refresh, or clean reinstall for startup crashes

Refresh Firefox clears extensions and modified settings while keeping bookmarks, passwords and history: menu (≡) → Help → More troubleshooting information → Refresh Firefox….
If Firefox crashes before you can do anything — even in Troubleshoot Mode — download the latest installer from mozilla.org and reinstall over the top. A clean reinstall does not delete your profile (bookmarks, passwords, add-ons), which is stored separately.

FAQ

What is a crash Report ID? After a crash, type about:crashes to see submitted reports. The Report ID helps Mozilla support diagnose a crash that survives Troubleshoot Mode.

Only one tab crashes, not the whole browser. That page or its content process failed. Reload it, and if it repeats, disable extensions that run on it (Fix 2). See also Chrome’s “Aw, Snap!” for the same pattern in another browser.

Sources: Mozilla Support — Troubleshoot Firefox crashes (closing or quitting unexpectedly)