Firefox takes a long time to start up

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  • Revision id: 23959
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  • Creator: Michael Verdi
  • Comment: for fx13 - added note about reset firefox feature, added info that tabs on demand is default for fx13, removed content specific to fx 4 - 7
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  • Reviewed by: Verdi
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  • Readied for localization by: Verdi
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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 Restore previous session - Configure when Firefox shows your most recent tabs and windows 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

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.

Use Windows Update to install a fix from Microsoft

This section only applies to Windows 7 or Windows Server 2008 R2.

Microsoft has released the recommended KB2505438 update that fixes slow startup performances in Firefox when HW acceleration is enabled. To make sure, you have this update installed:

  1. In Windows, click Small Vista Logo, select All programs, then select Windows Update. The Windows Update window will open.
  2. Click the "Check for updates" link and wait until it is done.
    • If no updates are available, you have this KB update installed. Skip to the next section.
  3. Click "n optional updates are available". The View available updates panel will appear.
  4. Click "Optional" and search KB2505438 in the list.
    • If you don't find it, you have this KB update installed. Skip to the next section.
  5. Check it and click OK to close the View available updates panel.
  6. Click Install updates.
  7. Restart your computer.
  8. Start Firefox and check if it loads faster.

Other solutions

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