Firefox can crash for a variety of reasons, but you can quickly fix most crashes with Firefox’s Safe Mode and Reset features. However, even these tricks won’t fix every crash.

Web browsers are complicated pieces of software that interact with lots of other software on your system — extensions and themes, plug-ins, security programs, graphics drivers, and more. Incompatibilities or out-of-date software can often cause crashes.

Use Safe Mode

Firefox has a Safe Mode that loads Firefox without loading your add-ons. To activate Safe Mode, click the Firefox menu, point to Help, and select Restart with Add-ons Disabled. You can also enter Safe Mode by holding the Shift key while starting Firefox.

Try using Safe Mode for a while if Firefox is crashing. If Safe Mode works properly, the problem is with one of your add-ons. You may want to leave Safe Mode and disable add-ons one-by-one until you identify the add-on causing the problem.

Reset Firefox

Firefox stores your personal data in a profile folder. Problems can occur with your profile folder, but you do not have to waste time identifying and fixing the exact cause. Firefox’s Reset feature will create a new profile folder, migrating over your bookmarks, browser history, saved passwords, cookies, and auto-fill information.

You will lose your extensions, themes, search engines, and site-specific preferences when you reset Firefox. Extensions and themes in particular can cause crashes, so getting rid of them and starting from a clean profile can be helpful.

To reset Firefox to its default state, open the Firefox menu, point to Help, and select Troubleshooting Information.

Click the Reset Firefox button. Firefox will create a new profile for you and migrate most of your old information over. The new, clean profile should hopefully fix your crashes.

If Firefox starts crashing again after you reinstall your favorite extensions, one of your extensions is likely causing the crashes. Try reinstalling extensions one-by-one to identify if a particular extension is causing problems.

Disable Hardware Acceleration

Firefox’s hardware acceleration feature uses your computer’s graphics card to render text and objects on web pages. This speeds up web page rendering and takes some load off your CPU. However, hardware acceleration can cause problems with some graphics drivers and graphics cards.

You can determine whether hardware acceleration is the problem by disabling it. To do so, click the Firefox button and select Options. Click the Advanced icon and uncheck the Use hardware acceleration when available checkbox.

Try using Firefox for a while after disabling this feature. If Firefox stops crashing, hardware acceleration was likely the problem. You can try installing updated graphics drivers and see if they fix the problem. If they don’t, you should leave hardware acceleration disabled on your system.

Note that you should not disable hardware acceleration if everything is working properly, as this is a useful feature.

Check for Malware

Malware can cause Firefox to crash, just as it can cause other programs to crash on your system. If Firefox is regularly crashing, scan your computer with an antivirus program like Microsoft Security Essentials. If you already have an antivirus program installed, you may want to get a second opinion from another antivirus program.

Update Software

Mozilla recommends updating the software on your system if Firefox is crashing. Here is a list of everything you should update:

  • Firefox: Click the Firefox menu, point to Help, and select About Firefox. Download and install any available updates.
  • Plug-ins: Visit the Firefox plug-in update check page. The page will scan your browser for outdated plugins. Follow the links to download and install updates for any outdated plugins.
  • Extensions and Themes: Click the Firefox button, click Add-ons, and select Extensions. Click the gear menu and select Check for Updates. Install any updated add-ons.
  • Windows: Use Windows Update to ensure Windows is up-to-date.
  • Graphics Drivers: Install updated graphics drivers to fix problems with hardware acceleration.
  • Internet Security Software: Install the latest versions of any firewalls, antivirus programs, Internet security suites, and other security applications installed on your system.

Hardware problems can also cause Firefox — and other software — to crash. Try checking your computer’s RAM for errors if crashes continue to occur.

Profile Photo for Chris Hoffman Chris Hoffman
Chris Hoffman is Editor-in-Chief of How-To Geek. He's written about technology for over a decade and was a PCWorld columnist for two years. Chris has written for The New York Times and Reader's Digest, been interviewed as a technology expert on TV stations like Miami's NBC 6, and had his work covered by news outlets like the BBC. Since 2011, Chris has written over 2,000 articles that have been read more than one billion times---and that's just here at How-To Geek.
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