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Firefox slows down on OSX

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  • Last reply by cor-el

dave.civello
dave.civello
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When using Firefox on OSX (Ventura 13.4) after about 1 day Firefox slows down so much I have to quit the application and restart it. Then it is back to normal speed. I'm not sure if this is an OS-X issue or Firefox issue, but restarting the app fixes it for a few hours, then its incredible slow again.

When using Firefox on OSX (Ventura 13.4) after about 1 day Firefox slows down so much I have to quit the application and restart it. Then it is back to normal speed. I'm not sure if this is an OS-X issue or Firefox issue, but restarting the app fixes it for a few hours, then its incredible slow again.

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cor-el
cor-el
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Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or if userChrome.css/userContent.css is causing the problem.

  • switch to the Default System theme: "3-bar" menu button or Tools -> Add-ons -> Themes
  • do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

You can create a new profile as a quick test to see if your current profile is causing the problem.

See "Creating a profile":

If the new profile works, you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.