Why Firefox is using 100% of CPU core when idle : Windows/Mac?


Firefox have recently released 100 version of the browser and its been remarkable for it. For many users Firefox is still the most reliable and fast browser and first choice to surf internet. The Firefox  is freezing and hogging CPU on different OS like Windows 11, MacOS Catalina etc.

Why Firefox is using 100% of CPU core when idle : Windows/Mac?
Firefox high CPU usage issue

But recently many users are reporting issue with the new version of Firefox being slow in loading and hogging CPU. Even if you won’t open any site or extension, still the Firefox is taking too much CPU. In multicore PC the Firefox is taking 100% of one core, which is surprising.

Other issue faced by Firefox user are like:

– Suddenly the browser will fail to load new links, but can browse within loaded webpages just fine (so long as no new resources need to be loaded)

– Every time user have to manually find and kill the problematic process to load up Firefox fresh


How to fix Firefox freezing / Suttering : Windows 11/ 2022

Fix : Try Troubleshoot mode

The Firefox high CPU usage could be linked to Windows bug or issue in the Firefox browser itself. To fix that you can try to run the Firefox browser in Troubleshoot Mode to detect and fix the issue in the Browser itself.  Please follow this guide for more details.

Fix : Clear the cache

If your Firefox browser is freezing or taking high CPU, them this coule be software glitch in the Firefox. To fix that clear cache from Firefox settings. Clearing the cache improves things form users but having to do this after every session and log onto every new site on startup is surely annoying .

 Fix : Update Firefox

There seems to be a similar bug reported to Firefox ( https://bugzilla.mozilla.org/show_bug.cgi?id=1763451). And per the status, the issue is fixed in the new release of Firefox. So please check for updates for the Firefox and keep updating the Firefox to new versions.

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