This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search 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.

Learn More

Firefox using excessing cpu resources also just tonight Adblock Plus addon doesn't allow pages to load

  • 1 phendula
  • 1 inayo le ngxaki
  • 9 views
  • Impendulo yokugqibela ngu ARMAN KHAN

more options

Anyone else notice excessive cpu usage with Firefox 77.0.1? It's been going on for the past week. 17.6-27% cpu usage just sitting here on the support page only after a fresh restart of the computer.

I also just noticed tonight not a single page would load. Switched to trouble shooting which disables the addons and pages loaded. Closed the browser and opened it again to be in normal mode and started disabling addons. The one I disabled to get pages to load again was Adblock Plus. Go figure of all the addons this is the one that is going to kill the browser from loading anything. I've already sent a report for this on the addon itself not sure what else to do there other then enjoy a bunch of adds for a while.

The one that concerns me more is Firefox just sucking away at the power for no reason at all. I can fill the top bar with tabs normally and not be using this much cpu. I would say it has developed a memory leak of sorts or something considering it's using 0 disk and network activity yet currently is using 18.4% cpu and 635MB memory for this single page being open.

Anyone else notice excessive cpu usage with Firefox 77.0.1? It's been going on for the past week. 17.6-27% cpu usage just sitting here on the support page only after a fresh restart of the computer. I also just noticed tonight not a single page would load. Switched to trouble shooting which disables the addons and pages loaded. Closed the browser and opened it again to be in normal mode and started disabling addons. The one I disabled to get pages to load again was Adblock Plus. Go figure of all the addons this is the one that is going to kill the browser from loading anything. I've already sent a report for this on the addon itself not sure what else to do there other then enjoy a bunch of adds for a while. The one that concerns me more is Firefox just sucking away at the power for no reason at all. I can fill the top bar with tabs normally and not be using this much cpu. I would say it has developed a memory leak of sorts or something considering it's using 0 disk and network activity yet currently is using 18.4% cpu and 635MB memory for this single page being open.

All Replies (1)

more options

hello scgt1


Check Flash hardware acceleration

If Adobe's Flash Player plugin is installed, rendering Flash content in full screen can be accelerated by hardware. This can ease resource usage in case of a dedicated graphics card.

  • Navigate to a page that shows a Flash video.
  • Right-click on the video player and click Settings… in the context menu. The Adobe Flash Player Settings screen will open.
  • Click on the icon at the bottom-left of the Adobe Flash Player Settings window to open the Display panel.
  • Check Enable hardware acceleration is selected.
  • Click Close to close the Adobe Flash Player Settings Window.

Close other applications

Having many applications running simultaneously may cause your computer to run slowly and other applications to do so as well. By closing down some of the unnecessary applications, system usage will be reduced.

Delete content-prefs.sqlite file

Firefox stores your data in various files in your profile folder.

The file used for saving individual website settings might be corrupt.

If you delete (or rename) that file, your zoom level settings will be reset but it could decrease CPU usage


  • Click the ≡ menu button
  • Click Help and select Troubleshooting Information. The Troubleshooting Information tab will open.

Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.

   Under the Application Basics section next to Profile Folder, click Open Folder.
Your profile folder will open. 
  • Click the Firefox menu ≡Menu and select Exit.
  • In your profile folder, delete the file content-prefs.sqlite. It will be recreated next time you open Firefox.

irefox tools

   The Firefox Task Manager (not to be confused with Windows Task Manager)
is a great tool to see what tabs and extensions are using the most system resources.
   The about:memory page allows you to troubleshoot specific issues relating to memory 

(for instance, caused by a website, an extension, a theme, etc.)

and sometimes its Minimize memory usage button may help you instantly reduce memory usage. 

For guidance on use of about:memory visit about:memory.

   Even if you're not a programmer, you can try your hand at some other tools and tips Firefox developers use to debug leaks. 

thank you and regards,

Arman