Troubleshoot and diagnose Firefox problems
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.
Table of Contents
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:
- Click the Library button
, click and select .
- In the Time Range to clear: drop-down, select Everything.
- Click the arrow next to Details to display the list of items that can be cleared.
- Select both Cookies and Cache.
- Click .
- Click the menu button
, choose and select .
- In the Time Range to clear: drop-down, select Everything.
- Click the arrow next to Details to display the list of items that can be cleared.
- Select both Cookies and Cache.
- Click .
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:
- Click the menu button
, click help
Click the menu button
, click and select . 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) - In the Firefox Safe Mode dialog, click .
- 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.
- Download the latest official version of Firefox from mozilla.org.
- Exit Firefox:
Click the menu button
and then click ExitQuit
.
Click the Firefox menu
, then click . Click the Firefox menu at the top of the screen, then click .Click the Firefox menu
, then click .
- Uninstall Firefox from your computer.
- Delete the Firefox program folder, which is located in one of these locations by default:
- C:\Program Files\Mozilla Firefox
- C:\Program Files (x86)\Mozilla Firefox
- Reinstall Firefox - see How to download and install Firefox on Windows for instructions.
- Download the latest official version of Firefox from mozilla.org.
- Quit Firefox:
Click the menu button
and then click ExitQuit
.
Click the Firefox menu
, then click . Click the Firefox menu at the top of the screen, then click .Click the Firefox menu
, then click .
- Uninstall Firefox from your computer by opening the Applications folder in the Finder and dragging the Firefox application to the Trash.
- Reinstall Firefox - see How to download and install Firefox on Mac for instructions.
- Download the latest official version of Firefox from mozilla.org.
- Quit Firefox:
Click the menu button
and then click ExitQuit
.
Click the Firefox menu
, then click . Click the Firefox menu at the top of the screen, then click .Click the Firefox menu
, then click .
- Uninstall Firefox - If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux for details. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory to uninstall Firefox.
- Reinstall Firefox - see Install Firefox on Linux for instructions.
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.
- Click this Refresh Firefox button directly, if you are viewing this page in Firefox.
This won't work if you are using a different browser or on a mobile device.- You can also find a Refresh Firefox button at the top of the Firefox about:support Troubleshooting Information page.
- To continue, click in the confirmation window that opens.
- Firefox will close to refresh itself. When finished, a window will list your imported information. Click 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
Beginning with Firefox version 52, support has ended for all NPAPI plugins except for Adobe Flash. See this compatibility document and this article for details.
-
Click the menu button
and choose . The Add-ons Manager tab will open.
- In the Add-ons Manager tab, select the panel.
- Click each plugin in the list and then select in its drop-down menu.
- 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 conflicts with your Internet security software
Some Internet security software (including antivirus, antispyware, and firewall programs) can cause problems with Firefox including blocking it from opening websites, crashes, and more. Often you can open the program's settings, remove Firefox from its list of allowed or trusted programs and it will be re-detected and things should start working again. If your program is listed at the Configure firewalls so that Firefox can access the Internet article, you can get specific instructions for how to properly reconfigure it.
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)