Nápověda k Firefoxu
Firefox hangs
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 becomes a spinning wait cursor 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 consumes a lot of CPU resources and High memory usage.
- If you get a "Warning: Unresponsive script" prompt, see Warning Unresponsive script.
- If Firefox closes unexpectedly, see Firefox crashes.
To resolve hanging problems not specifically mentioned in this article, or if the suggested solutions do not solve the problem, see Basic Troubleshooting.
Table of Contents
Firefox hangs at random times
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:
Open your profile folder:
- At the top of the Firefox windowOn the menu bar, click on the menuAt the top of the Firefox window, click on the button, go over to the menu (on Windows XP, click on the menu)On the menu bar, click on the menuAt the top of the Firefox window, click on the menu and select . The Troubleshooting Information tab will open.
- Under the Application Basics section, click on . A window with your profile filesfolder will open.Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.
- At the top of the Firefox window, click on the button ( menu in Windows XP) and then click On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select At the top of the Firefox window, click on the menu and select On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select . Wait until Firefox has completely quit.
- In the Firefox profile folder, find and rename the files places.sqlite and places.sqlite-journal (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.
- 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.
- At the top of the Firefox window, click on the button ( menu in Windows XP) and then click On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select At the top of the Firefox window, click on the menu and select On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select
- Select the panel and the tab.
- Uncheck Use hardware acceleration when available.
- At the top of the Firefox window, click on the button ( menu in Windows XP) and then click On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select At the top of the Firefox window, click on the menu and select On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select .
- 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.
Troubleshoot your plugins
Sites that use plugins such as Java, Adobe Reader, or Flash can cause Firefox to hang. For information on troubleshooting plugins and on determining whether a plugin is causing your problem, see the Troubleshooting plugins article.
Delete duplicated Session Restore files
Firefox may be slow to respond or hang if multiple copies of its Session Restore file have been created:
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Open your profile folder:
- At the top of the Firefox windowOn the menu bar, click on the menuAt the top of the Firefox window, click on the button, go over to the menu (on Windows XP, click on the menu)On the menu bar, click on the menuAt the top of the Firefox window, click on the menu and select . The Troubleshooting Information tab will open.
- Under the Application Basics section, click on . A window with your profile filesfolder will open.Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.
- At the top of the Firefox window, click on the button ( menu in Windows XP) and then click On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select At the top of the Firefox window, click on the menu and select On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select .
- 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:
- At the top of the Firefox window, click on the button ( menu in Windows XP) and then click On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select At the top of the Firefox window, click on the menu and select On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select
- Click the icon.
- Click the tab.
- Click . The Connection Settings dialog appears.
- 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.
- Click .
Firefox hangs while playing Flash videos
See Playing Flash videos makes Firefox hang.
Firefox hangs after using it for a long time
Update Firefox
The latest Firefox version includes improvements about memory usage, including during long sessions (for details, see this Mozilla developer's article). 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.
Firefox hangs while loading the first window
Speed up Session Restore
If you have many tabs to restore, Firefox may hang while loading those sites. Check Don't load tabs until selected in the General panel of the OptionsPreferences window so that only the last selected tab is loaded at startup.Try to use Tab Groups so that only websites in the visible tab group load first.
Disable hyper-threading for Firefox with a Pentium 4
A Firefox hang on computers with Intel Pentium 4 processors while loading the first browser window may be caused by "hyper-threading", a feature designed to improve performance.
If your computer has an Intel Pentium 4 processor and you use Windows 2000 and XP, you can disable hyper-threading for Firefox:
- Open the System Information window following steps in Description of Windows XP System Information (Msinfo32.exe) Tool at microsoft.com
- Make sure your processor is an Intel Pentium 4
- If your processor is not an Intel Pentium 4, skip the next steps of this section.
- Right-click the shortcut icon you use to start Firefox.
- Select .
- Select the icon.
- Select Run this program in compatibility mode.
- In the drop-down for compatibility mode, select Windows 98/Windows ME.
- Click .
- Restart Firefox to see if the hanging has gone away.
Firefox hangs when downloading files or saving images
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:
- At the top of the Firefox window, click on the button ( menu in Windows XP), and then click At the top of the Firefox window, click on the menu, and then click On the menu bar, click on the menu, and then click At the top of the Firefox window, click on the menu, and then click . The Downloads window will open.
- Click . The download history is cleared.
- 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:
- At the top of the Firefox window, click on the button ( menu in Windows XP) and then click On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select At the top of the Firefox window, click on the menu and select On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select
- Select the panel.
- In the Downloads pane, select Save files to and click the button.
- In the Browse For Folder window, choose a new folder location.
- Click to close the Options windowClick to close the Preferences windowClose the Preferences window
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 .
Disable virus scan in Firefox preferences
With some antivirus programs, the virus scan that Firefox starts after files are downloaded may cause Firefox to hang. You can disable virus scanning with the following steps (this will not disable your antivirus program):
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In the Location bar, type about:config and press EnterReturn.
- The about:config "This might void your warranty!" warning page may appear. Click , to continue to the about:config page.
- Locate the browser.download.manager.scanWhenDone preference and double click it to change the value to false.
Firefox hangs when you quit it
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 the message, Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.. 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 for other causes and solutions).
Close Firefox completely
- At the top of the Firefox window, click on the button ( menu in Windows XP) and then click On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select At the top of the Firefox window, click on the menu and select On the menu bar, click on the menu and select At the top of the Firefox window, click on the menu and select .
- Close any remaining dialog boxes or secondary windows such as the Downloads window or the Add-ons 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 Troubleshooting extensions and themes article.
Update or disable the Java plugin
Sometimes Java applets can cause the Firefox process to persist after exit. Try updating Java to the latest version by going to Mozilla's plugin check page or, if you don't need the Java plugin, you can disable it from the Plugins panel of the Firefox Add-ons Manager. For more information, see Using the Java plugin with Firefox.
Troubleshoot your Internet security software
Interactions between certain Internet security software (firewall, anti-virus software) is reported to cause the issue on some systems.
Based on information from Firefox hangs (mozillaZine KB)
