Join us to show up for other Firefox users 🦊. Earn fun badges and Mozilla swag vouchers! Find out more: https://mzl.la/askafox150

Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

Søg i Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Læs mere

Firefox Unusable Because of Excessive CPU Usage

  • 4 svar
  • 0 har dette problem
  • 17 visninger
  • Seneste svar af Paul
  • Åben

I've just opened one simple Web site (in addition to Mozilla), and already CPU usage sits at about 20%! Please refer to my recent posts here at "Why is Firefox Suddenly Taking Over my CPU?" for the problem description. I'm re-posting simply in hopes that I can "send data" on this one from outside my sandbox. Regards -- jclarkw

I've just opened one simple Web site (in addition to Mozilla), and already CPU usage sits at about 20%! Please refer to my recent posts here at "Why is Firefox Suddenly Taking Over my CPU?" for the problem description. I'm re-posting simply in hopes that I can "send data" on this one from outside my sandbox. Regards -- jclarkw

Alle svar (4)

Reply Removed -- jclarkw

Ændret af jclarkw den

Hello,

Here are some issues that have been found to be solutions :

  • extensions (check every extension)
  • Heavy webpage content ( if the site has lots of animations and stuff, open task manager and see if that tab is the reason)
  • Hardware acceleration issues : Try disabling it in Settings > General > Performance.
  • Outdated graphics drivers (update in device manager)
  • Clear cache and cookies or refreshing Firefox (Note that cookies can sign you out of some websites.
  • or Malware

If not, it is most likely because that the CPU is older, and can't handle as much. Especially for one of my computers, sometimes it takes up to 50% CPU load when streaming videos.

Dear dessertdish -- Thanks much for the suggestions! One note regarding your old-hardware point: Although the hardware is indeed old, I also run Chrome on it; and moving the offending Web sites to Chrome, although it relieves the CPU usage by Firefox, does not replace it with a comparable usage by Chrome. This and the fact that the problem seemed to have a suddent (recent) onset suggested to me that it was a Firefox issue.

The best (unsatisfying) solution so far has been to use Chrome for anything that causes Firefox to load down the computer. Cheers! -- jclarkw

Hi

Are you able to share the address of the website that is causing this to happen?

Does this only happen with this one website?

Stil et spørgsmål

Du skal logge ind på din konto for at svare på et indlæg. Start et nyt spørgsmål, hvis du ikke har en konto endnu.