Question Memory leak with Windows 11 and Firefox

[bigboxes]

Two months ago, I upgraded from Windows 10 to Windows 11. I was noticing that my rig (in my sig) was getting sluggish. I opened up task manager and I noticed that my memory usage was at 49%. Normally, it runs at 25% or less. I've got 32GB of ram. So, it's been normal for 8GB or less of ram usage at idle. I leave around 20 tabs open all of the time. I've never had stability issues with this rig (in my sig) for over three years. The only difference has been the upgrade to Windows 11. I haven't experienced a memory leak like this since my last rig (4790K) and Windows 7. I thought that FF had things all straightened out. Is this a FF issue or is this a Windows 11 issue? The ram usage keep on creeping higher. Tonight is hovering at 44%. I've tried resmon and checked the memory tab. In an effort to troubleshoot, I've disabled uBlock Origin and turned off YouTube. Does not cut mem usage. Anyone else experiencing this?

 

[bigboxes]

It just got to 49% and real sluggish. Had to reboot. Back to 25%. Anyone know of this memory leak?

 

[balloonshark]

I have 6 tabs open and I see 20 firefox processes in task manager. I'm using 40% memory total and I have 32GB ram. I also run firefox sandboxed and it runs in my memory (ram disk) and not my SSD.

Firefox also has a task manager if you want to see if something is using a lot of memory. Click the Firefox hamburger menu - More Tools and click Task Manager.

 

[VirtualLarry]

It's (mostly) YouTube's video-player applet.

 

[ZoeAndersen]

Upgrading to Windows 11 shouldn't cause such a big jump in memory usage, but there could be a few things at play here. Given that you leave around 20 tabs open all the time, it's possible that Firefox is the culprit. Even though Firefox generally handles memory better now, certain sites or tabs—especially those with heavy JavaScript or ads—can still cause memory usage to creep up over time. Disabling uBlock Origin or closing YouTube might not immediately reflect in decreased memory usage because those processes could still be lingering in the background.
Firefox is high up there, that's a sign it might be the issue. Just for testing, try restarting Firefox entirely and see if memory usage drops significantly—if it does, that points to Firefox as the main issue. Running Firefox in Safe Mode could also help determine if an add-on might be causing the memory leak.