This article describes some causes of a long start up time and steps you can take to improve it.

• If Firefox starts but isn't responsive, see Firefox hangs or is not responding - How to fix.
• If Firefox does not start up at all, see Firefox won't start - find solutions.

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.

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.

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.