Mozilla Firefox Freezing or Crashing on Windows computer

Are you a Firefox user? If yes, you might have come across an instance where the browser suddenly freezes or hangs or crashes and closes down unexpectedly or collapses into a not responding mode.

Freezing or Hanging is a process where a program stops responding to a user’s input. A hang, or a freeze is different from a crash. A Crash ends the program, and the windows automatically shuts down. The reasons can be many. It could the installation of incompatible themes, extensions or programming errors in plugins. I am suggesting below some troubleshooting steps which you could follow in case you find that your Firefox is giving you problems in Windows.

Firefox Freezes or Crashes

Clear Firefox Browser Cache, History and Download History

  • Files take longer to download as the download history builds up. To fix up this freeze, go to Firefox menu, then ‘Downloads’ and click on ‘Clear List’ to clear the Download History.
  • Also, if the folder where Firefox is attempting to save the file is not accessible, it can freeze.
  • Try resetting the preference in about:config. You can also try choosing a new download folder in your Firefox settings (Tools -> Options -> General ( or Main) / Downloads -> Save files to -> Browse).

  •  At times Browsing History interferes with the browser start-up and therefore can hang Firefox for indefinite periods.
  • Clear the History to avoid this instance. For this, first go to Tools > ‘Clear Recent History‘ to see if it resolves the problem.

You could also consider using CCleaner to clear up your entire Firefox Cache, etc.

Bad Firefox Add-on

My next suggestion would be for you to switch Firefox to Safe-mode and check out if you have any bad add-ons installed. If the Firefox browser freezes without any warning when you type something or click on a button link, close all the tabs and start Firefox in Safe mode.

To do this:

  1. Go to Start > All programs > Mozilla Firefox > Safe mode
  2.  Now, if Firefox runs without freezing, it suggests a bad add-on – either an extension or toolbar – some extensions are prone to memory leaks
  3. Next, go to Tools > Add-ons and disable each one, one after the other and try to find out the culprit. If you are able to identoify the offending add-on or extension or toolbar, uninstall it.

Update Adobe Flash version

  • If you are facing freezing or experiencing a  delay while starting Firefox, you might want to check out if your Adobe Flash, Java plugins are up-to-date. Some versions did cause Firefox to freeze or crash. This page will tell you which version of Adobe Flash, you have installed.
  • For more info, visit Adobe Flash Player Download Center.

Check Windows shell extensions

Some Windows shell extensions can also cause problems with your Firefox browser, causing it to freeze or crash. You cans use ShellExView to see all the explorer shell extensions and then try to selectively disable extensions which you suspect could be the cause for your problems.



Extensions of 3rd party software

Extensions of your antivirus, security suite, site advisors, password manager, download managers could also be a possible cause. Again, disable each one selectively and see if you can identify the offending issue.

Create a new Profile

The Firefox User Profile Manager allows you to create an additional profile. Create a new profile on Firefox and transfer all your settings and  stuff to the new profile, and see if it helps.

Reduce Firefox memory usage

You may also want to consider reducing memory usage of Firefox by changing the about:config preferences. You may especially want to tweak the browser.cache.memory.capacity, bowser.cache.memory.enable and browser.sessionhistory.max_total_viewers settings. But do so only if you know what you are doing. Reducing the memory usage by carrying out just tweaks, removing themes, personas and reducing add-ons or plugins can also help you resolve your problem.

Also read: Firefox keeps slowing down on Windows.

If it doesn’t, you may want to reset Firefox settings. In later versions of Firefox, you will see a Refresh Firefox – Give Firefox a tune up button, instead of Reset Firefox. You can also Tune up and Refresh Mozilla Firefox browser online.

We hope that something here helps you resolve your problem. If you have any more tips to share for the benefit of others, please do so in the comments below. If you need more help, you can always visit our Windows Help Forum.

Fix Freezes or Crashes with these resources from TheWindowsClub:

Windows 7 freezes | Windows Explorer crashes | Internet Explorer freezing| Google Chrome Browser crashes | Mozilla Firefox Browser freezing | Windows Media Player freezes | Computer hardware freezes. Need more? Try FixWin, the Windows Doctor!

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Anand Khanse is the Admin of and a 10-year Microsoft MVP Awardee in Windows for the period 2006-16. Please read the entire post & the comments first, create a System Restore Point before making any changes to your system & be careful about any 3rd-party offers while installing freeware.