Most problems with Firefox can be fixed by following the troubleshooting methods described below. Try these steps in order. If one doesn't work, move on to the next one. If you need extra help with any of this, we have a community of volunteers standing by.

1. Restart your computer

Sometimes problems can be fixed by simply restarting your computer and then starting Firefox again.

2. Clear your cookies and cache

Many problems with loading web pages can be resolved by clearing Firefox's cookies and cache:

1. Click the menu button , choose History and select Clear Recent History....
2. In the Time Range to clear: drop-down, select Everything.
3. Click the arrow next to Details to display the list of items that can be cleared.
4. Select both Cookies and Cache.
5. Click Clear Now.

3. Restart Firefox in Safe Mode

Firefox Safe Mode is a troubleshooting mode that disables all extensions, uses the default theme, turns off hardware acceleration, and uses default toolbar settings and controls, among other things. To start Firefox in Safe Mode:

1. Click the menu button , click help and select Restart with Add-ons Disabled.... Firefox will start up with the Firefox Safe Mode dialog.
   Note: You can also start Firefox in Safe Mode by holding down the shift key while starting Firefox.holding down the option key while starting Firefox.quitting Firefox and then going to your Terminal and running: firefox -safe-mode
   You may need to specify the Firefox installation path (e.g. /usr/lib/firefox)
2. In the Firefox Safe Mode dialog, click Start in Safe Mode.
3. Check whether your problem is still happening while in Safe Mode.

• If the problem still happens in Safe Mode, go on to step 4.
• If the problem does not happen in Safe Mode, see the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article and follow the instructions under The problem does not occur in Safe Mode to narrow down the cause.

4. Reinstall Firefox

Some Firefox issues can be caused by a problem with one of the Firefox program files. Follow these steps to completely remove and reinstall Firefox. This process will not remove your Firefox profile data (such as bookmarks and passwords), since that information is stored in a different location.

Now start Firefox and check to see if your problem has been fixed. If it hasn't, continue with the next troubleshooting method.

5. Refresh Firefox

The Refresh Firefox feature can fix many issues by restoring your Firefox profile to its default state while saving your essential information.

1. Click the menu button and then click help .
2. From the Help menu choose Troubleshooting Information.

   If you're unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting Information page.

3. Click the Refresh Firefox button in the upper-right corner of the Troubleshooting Information page.

   

4. To continue, click Refresh Firefox in the confirmation window that opens.
5. Firefox will close to refresh itself. When finished, a window will list your imported information. Click Finish and Firefox will open.

6. Create a new Firefox profile

Sometimes files in your Firefox profile folder that correspond to the essential information that a Firefox Refresh doesn't remove (such as bookmarks and browsing history) may be causing the issue. You can create a new, additional profile which will not contain any of your old Firefox data. See Use the Profile Manager to create and remove Firefox profiles for instructions.

Other solutions

If you've tried all of these troubleshooting methods and you're still having problems, the issue may be with other software or hardware on your computer.

For more information on any of these solutions, please check the related documentation.

Troubleshoot your plugins

1. Click the menu button and choose Add-ons. The Add-ons Manager tab will open.

2. In the Add-ons Manager tab, select the Plugins panel.
3. Click each plugin in the list and then select Never Activate in its drop-down menu.
4. Check whether your problem happens when you have all plugins disabled.

If your problem goes away when your plugins are disabled, see the Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems article to learn how to narrow down the cause.

Check for malware

Malware (short for "malicious software") can cause problems with Firefox. Periodically, you should scan your system for viruses, spyware, or other malware. For more information, see Troubleshoot Firefox issues caused by malware.

Based on information from Standard diagnostic - Firefox (mozillaZine KB)