Firefox takes a long time to start up

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  • Revision id: 31300
  • Created:
  • Creator: scoobidiver
  • Comment: KB2505438 now included in Win 7 SP1, fixed links, added keyword
  • Reviewed: Yes
  • Reviewed:
  • Reviewed by: Ibai
  • Is approved? Yes
  • Is current revision? No
  • Ready for localization: Yes
  • Readied for localization:
  • Readied for localization by: Ibai
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This article describes some causes of a long start up time and steps you can take to improve it.

Note: The Refresh Firefox feature can fix many issues by restoring Firefox to its default state while saving your essential information. Consider using it before going through a lengthy troubleshooting process.

Change the home page

Problems with a website can cause Firefox to take a long time to start. Try changing your Firefox home page to the default home page or a blank page. See How to set the home page for instructions.

Change how windows and tabs are loaded

If you set Firefox to use the Session Restore feature to show your windows and tabs from last time, Firefox can take a long time to start if you had lots of websites open the last time you used Firefox. 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.

Startup-loadtabs

If you set Firefox to use the Session Restore feature to show your windows and tabs from last time, Firefox can take a long time to start if you had lots of websites open the last time you used Firefox. 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 (This should be the default setting).

Startup-loadtabs

If you set Firefox to use the Session Restore feature to show your windows and tabs from last time, Firefox can take a long time to start if you had lots of websites open the last time you used Firefox. Check Don't load tabs until selected in the Tabs panel of the OptionsPreferences window so that only the last selected tab is loaded at startup (This should be the default setting).

Check your antivirus software

Firefox reads a number of files normally during startup. Some antivirus software may do intensive scans of each of these files during startup and block access until those scans complete. If the problem began after installing, updating, or reconfiguring your antivirus software, contact the software provider for assistance.

Troubleshoot extensions or themes

Firefox loads extensions when it starts up and many extensions add startup tasks. See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems for steps on how to identify an extension that may be causing the problem.

Optimize Windows

Speed up Windows and make your computer work better. See Optimize Windows 7 for better performance where some recommendations are also applicable to other Windows versions.

Other solutions

If the previous suggestions don't significantly reduce Firefox startup time, see Troubleshoot and diagnose Firefox problems for other steps you can take to resolve the problem.