Dec 19, 2020 Another way to speed up Firefox along and your macOS, in general, is to use CleanMyMac X. In a couple of quick clicks the app will find and, with your approval, remove unneeded system files from all over your macOS - including your Firefox cache and browser history. To clean up Firefox caches, and other browser junk the easy way. In the Apple Menu, select the Force Quit option (you can also use the Command – Option – Esc combination); In the pop-up window, click on the Force Quit button to close Firefox. If the entire system is frozen, it is necessary to make a hard reboot by holding the power button for a few seconds.

1. Firefox Not Responding Mac Os
2. Firefox Not Responding On Mac
3. Firefox Not Responding On My Mac
4. Mozilla Firefox Not Responding
5. Firefox Keeps Not Responding

When Firefox hangs, it stops responding to your clicks and keystrokes and doesn't seem to be doing anything. Also, a '(Not Responding)' label is displayed in the title bar and the mouse cursor becomes a spinning wheel when it's over the Firefox window.Also, the mouse becomes a spinning wait cursor when it's over the Firefox window. This article gives you solutions to Firefox hangs depending on when they happen.

• If Firefox uses a lot of computer resources, see the solutions proposed in Firefox uses too much memory or CPU resources - How to fix.
• If you get a 'Warning: Unresponsive script' prompt, see Warning Unresponsive script - What it means and how to fix it.
• If Firefox closes unexpectedly, see Troubleshoot Firefox crashes (closing or quitting unexpectedly).

To resolve hanging problems not specifically mentioned in this article, or if the suggested solutions do not solve the problem, see Troubleshoot and diagnose Firefox problems.

Table of Contents

• 1Firefox hangs at random times
• 3Firefox hangs after using it for a long time
• 4Firefox hangs when downloading files or saving images
• 5Firefox hangs when you quit it

If Firefox seems to hang randomly and not after a specific action (for example, downloading a file or quitting Firefox), try the solutions in this section.

Create a new places database

If hangs are periodic, it may be caused by a corrupted places database.

To create a new places database, do the following:

1. Open your profile folder:

   • Click the menu button , click Help and select Troubleshooting InformationMore Troubleshooting Information.From the Help menu, select Troubleshooting InformationMore Troubleshooting Information. The Troubleshooting Information tab will open.
   • Under the Application Basics section next to Profile FolderDirectory, click . A window will open that contains your profile folder.Your profile folder will open.
   Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.
2. Click the Firefox menu and select Exit.Click the Firefox menu at the top of the screen and select Quit Firefox.Click the Firefox menu and select Quit. Wait until Firefox has completely quit.
3. In the Firefox profile folder, find and rename the files places.sqlite to places.sqlite.old and places.sqlite-journal to places.sqlite-journal.old (if it exists).
   • To rename a file, right-click on it and select rename from the menuclick on it once to select it and then click a second time on the file name to make it editable. Then add .old to the end of its name.
4. Finally, reopen Firefox.
   • When Firefox reopens it will create a new places database. Your browsing history will be lost but Firefox will automatically import your bookmarks from the most recent backup file.

Turn off hardware acceleration

With some graphics card and graphics driver setups, Firefox may hang when using hardware acceleration. You can try turning off hardware acceleration to see if it fixes the problem.

Firefox Not Responding Mac Os

1. In the Menu bar at the top of the screen, click Firefox and select Preferences.Click the menu button and select ...
2. Select the Advanced panel and the General tab.
3. Uncheck Use hardware acceleration when available.
4. Click the Firefox menu and select Exit.Click the Firefox menu at the top of the screen and select Quit Firefox.Click the Firefox menu and select Quit.
5. Start Firefox the way you normally do.

1. In the Menu bar at the top of the screen, click Firefox and select Preferences.Click the menu button and select ...
2. Select the General panel.
3. Under Performance, uncheck Use recommended performance settings.
   Additional settings will be displayed.
4. Uncheck Use hardware acceleration when available.
5. Click the Firefox menu and select Exit.Click the Firefox menu at the top of the screen and select Quit Firefox.Click the Firefox menu and select Quit.
6. Start Firefox the way you normally do.

If the problem is no longer happening, then hardware acceleration was likely the cause. You can try updating your graphics drivers to see if that fixes it or simply run without hardware acceleration.

Delete duplicated Session Restore files

Firefox may be slow to respond or hang if multiple copies of its Session Restore file have been created:

1. Open your profile folder:

   • Click the menu button , click Help and select Troubleshooting InformationMore Troubleshooting Information.From the Help menu, select Troubleshooting InformationMore Troubleshooting Information. The Troubleshooting Information tab will open.
   • Under the Application Basics section next to Profile FolderDirectory, click . A window will open that contains your profile folder.Your profile folder will open.
   Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.
2. Click the Firefox menu and select Exit.Click the Firefox menu at the top of the screen and select Quit Firefox.Click the Firefox menu and select Quit.
3. Locate and delete the sessionstore.js file and any copies, such as sessionstore-1.js, sessionstore-2.js.

Change the PAC implementation

If you're using a proxy auto-config file (PAC), Firefox may hang when you attempt to load sites that don't exist or that you haven't opened recently. To determine if you use an automatic proxy configuration file:

1. In the Menu bar at the top of the screen, click Firefox and select Preferences.Click the menu button and select ...
2. In the General panel, go down to the Network ProxyNetwork Settings section.
3. Click . The Connection Settings dialog appears.
4. If Automatic proxy configuration URL is selected, you are using an automatic proxy configuration file. Do not disable this setting, which will prevent you from accessing the Internet. Instead, provide this workaround to your network administrator.
5. Click .

See Playing Flash videos makes Firefox hang.

Firefox Not Responding On Mac

Update Firefox

The latest Firefox versions includes improvements in memory usage, especially during long sessions. Update Firefox to the latest version.

Restart Firefox

Firefox may hang if left open for long periods of time. To fix the issue, restart Firefox.

If you regularly leave Firefox open so that you return to where you left off, you may want to use Firefox's Session Restore feature. For more information, see Configuring session restore.

If Firefox hangs when you attempt to download a file or save an image, try these solutions:

Clear download history

Firefox may hang when downloading files if your download history has grown too large. To clear the download history:

Firefox Not Responding On My Mac

1. Click the Downloads button on the toolbar, if it's available, or else click the Library button and click Downloads from the menu.
2. Click Show All Downloads at the bottom of the Downloads panel. The Library window will open.
3. Click the button at the top of the Library window.
4. Download some sample files to see if the hanging has stopped.

Choose a different download folder

Firefox may hang if the last download folder location (e.g. a shared volume or USB drive) is no longer available. To fix this:

1. In the Menu bar at the top of the screen, click Firefox and select Preferences.Click the menu button and select ...
2. Select the General panel.
3. Under Downloads, select Save files to and click the button.
4. In the Choose Download Folder window, choose a new folder location.
5. Close the about:preferences page. Any changes you've made will automatically be saved.

See if you are now able to download files or save images. If this works, you can go back to your Firefox settings, if you wish, and select Always ask me where to save my files.

Sometimes when you close Firefox, it may stop responding and remain in memory, even though no Firefox windows are open. This can prevent Firefox from working properly the next time you open it or you may see a 'Close Firefox' dialog box with an error message, Firefox is already running, but is not responding.A copy of Firefox is already open. You must then end all Firefox processes or restart the computer before you can reopen Firefox (see 'Firefox is already running but is not responding' error - How to fix for other causes and solutions).

Close Firefox completely

1. Click the Firefox menu and select Exit.Click the Firefox menu at the top of the screen and select Quit Firefox.Click the Firefox menu and select Quit.
2. Close any remaining dialog boxes or secondary windows such as the Library window.

If Firefox processes that remain in memory at exit are a recurring problem, try the following solutions.

Troubleshoot your extensions

A problematic extension can cause the problem, which can be resolved by disabling or uninstalling the extension. For information on diagnosing and fixing problems caused by faulty extensions, see the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article.

Troubleshoot your Internet security software

Mozilla Firefox Not Responding

Interactions between certain Internet security software (firewall, anti-virus software) is reported to cause hangs on some systems. You can try to configure your firewall to see if it helps the hang go away.

Firefox Keeps Not Responding

When resuming Windows from hibernation and Firefox hangs for several minutes it might be due to an issue of the pre-installed 'ThinkVantage Technologies Power Manager 6'. One option to solve this is to uninstall the software. Another option is to check for a later version of the software on the Lenovo support website and see if that fixes the problem. See Bug 1106202 for more details.

Based on information from Firefox hangs (mozillaZine KB)