topic Re: Browser Firefox for Mac version 142.0.1 is a memory hog on some websites in Discussions

Browser Firefox for Mac version 142.0.1 is a memory hog on some websites

pierrenaud — Mon, 15 Sep 2025 17:58:04 GMT

On some news sites like CTVnews.ca and others https://www.reuters.com/, Firefox is using all 16GB of memory on my iMac in a matter of 30-60 seconds.

I am using the Mac Application Activity Monitor to track my memory usage. My computer is an iMac 27 inch made in 2020.

The application itself seems to be using anywhere from 700MB to up to 8 GB while running. My problem seem to be related to files called "Firefox Isolated Web Content". There are anywhere from as few as 5-8 files to as many as 20 files or more with that name. The file size varies from 1 to 7 GB each.

If I dont kill these file my computer freezes/crashes on a regular basis.

I would appreciate any help I can get.

When I use Google chrome on these same websites. There are no memory related problems on these same websites

Re: Browser Firefox for Mac version 142.0.1 is a memory hog on some websites

siffemcon — Tue, 16 Sep 2025 02:15:46 GMT

You could file a bug:

- via the address bar, go to about:crashes and submit all pending crash reports. Copy the ID of the most recent report.

- via the address bar, go to about:support > click 'Copy text to clipboard' > paste to a text editor and save it as a plain text file

- via the address bar, open about:memory in a new tab > click 'Measure and save'

- file the bug at https://bugzilla.mozilla.org/enter_bug.cgi/?

- click the 'Attach New File' button to upload your saved files. Also mention your last crash ID.

Re: Browser Firefox for Mac version 142.0.1 is a memory hog on some websites

Kovant — Tue, 16 Sep 2025 03:02:01 GMT

Could you please help me test this website: https://www.link-pp.com/ to see if this situation occurs? I also experience lag when I test it myself, but Google chrome works fine. I don't know what the problem is. Thank you.

Re: Browser Firefox for Mac version 142.0.1 is a memory hog on some websites

siffemcon — Tue, 16 Sep 2025 07:44:36 GMT

Works for me on FF 142/Win11.

You can file a compatibility issue

- via the 'Report broken site' option (https://support.mozilla.org/en-US/kb/report-breakage-due-blocking) (Send technical and interaction data to Mozilla must be enabled)

- on webcompat.com (https://webcompat.com/issues/new), esp. if you want to include a screenshot)