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Firefox 19 suddenly became very slow after using it for about an hour.

  • 3 replies
  • 7 have this problem
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  • Last reply by dan733

dan733
dan733
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I've been using firefox 19 since it came out and have experienced no problems. Now today after about an hour of using the browser it has become so slow to the point where it becomes unresponsive for about ten seconds when I try to switch to a different tab. What is strange is that when I run firefox in safe mode, its fine, but I haven't downloaded any addons for a few weeks. Any help would be appreciated.

I've been using firefox 19 since it came out and have experienced no problems. Now today after about an hour of using the browser it has become so slow to the point where it becomes unresponsive for about ten seconds when I try to switch to a different tab. What is strange is that when I run firefox in safe mode, its fine, but I haven't downloaded any addons for a few weeks. Any help would be appreciated.

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iamjayakumars
iamjayakumars
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  • Remove your Unwanted Extensions
  • updated your plugins


Many site issues can be caused by corrupt cookies or cache. In order to try to fix these problems, the first step is to clear both cookies and the cache. Note: This will temporarily log you out of all sites you're logged in to. To clear cache and cookies do the following:


  1. Go to Firefox > History > Clear recent history or (if no Firefox button is shown) go to Tools > Clear recent history.
  2. Under "Time range to clear", select "Everything".
  3. Now, click the arrow next to Details to toggle the Details list active.
  4. From the details list, check Cache and Cookies and uncheck everything else.
  5. Now click the Clear now button.

Further information can be found in the Clear your cache, history and other personal information in Firefox article.

Did this fix your problems? Please report back to us!

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
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Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

  • Do NOT click the Reset button on the Safe mode start window or otherwise make changes.

Which security software (firewall, anti-virus) do you have?

Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

dan733
dan733 Question owner
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Thanks for the help guys! I didn't think it was an extension because it had been a while since I downloaded one, but the culprit turned out to be TabGroups Manager. Glad I have firefox back, I was scared I'd have to get used to Chrome!