2001788 - macOS Memory Crash

Status: UNCONFIRMED

(Core :: Performance: Memory, defect)

Description

[S3V3RIN]

Attachment: Activity Monitor, About This Mac, & Force Quit Applications pop-up boxes

User Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 26_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) FxiOS/145.0 Mobile/15E148 Safari/604.1

Steps to reproduce:

1. Open 25 tabs of various websites and streaming platforms.

2. Keep Mac on for a week or two. Use it every day like normal.

3. When websites and searches are lagging, you're nearing the crash. Continue using Firefox as normal.

4. Eventually, your Mac will ask to force close Firefox and your laptop gets paralyzed until you do. 'Force Quit Applications' will appear and say "Your system has run out of application memory"

5. Force quit Firefox and the cycle begins again.

Random Search Tags (In case other people come by): macOS Sequoia 15 memory 8 GB RAM crashing 46 GB memory Macbook Air freezing force quit excessive application Firefox issue memory tabs memory leak memory management – if anyone else is searching for a solution and something like this lowkey happens to you please add a comment below

Actual results:

Specs: M1 2020 MacBook Air with 8 GB Memory running Sequoia 15.6. My Firefox is updated to 145.0.1 (aarch64) as of Nov. 22nd, 2025. After the crash, I opened about:memory in Firefox and the "Total resident memory" says 1,146.56 MB. I did get the extension Auto Tab Discard because this crash has happened a few times already. I switched to Firefox earlier this year.

There's a picture from my phone of Activity Monitor & the Force Quit pop-up attached below. Next time Firefox begins to slow down, I'll go to About:Memory and get a proper measure of what's happening right before it crashes.

I just had a few Google Docs, a streaming site, and a couple random searches open before my Mac got super lagging and then just stopped. The Force Quit Application box popped up and said Firefox stalled at 46.66 GB of memory.

I've been trying to close all my Firefox tabs and restart at the end of each week to avoid this. Screenshotting and other Mac functions also get paralyzed whenever this happens. Usually, I don't notice Firefox getting slower until it takes 2-3 minutes to load a Google Search. By that point, Firefox crashing is inevitable.

Expected results:

I don't really understand RAM and memory efficiency on Macs in general but I just don't think Firefox should be using 46 GB of memory.

I expected that Firefox would be chill staying open on my laptop when I leave it on forever. With Chrome, I used to never turn off my Mac and I'd just put it to sleep while charging it constantly. I thought Auto Tab Discard would've paused tabs I haven't opened in a few hours so they wouldn't use more memory in the background but I don't know if that's working either.

I use hella tabs for random searches, work from different classes, and other various projects so I expect Firefox to stay alive with all that going on. It's hard to close half-finished stuff which is why my Macs perpetually on and just sleeps instead.

I also never turn off my iPhone and have so many more open tabs on Firefox Mobile but this never happens with my phone.

Comment 1

[S3V3RIN]

Help

Comment 2

[S3V3RIN]

I'll update with the "About:Memory" website measurement from before Firefox crashes the next time this happens. I think I can catch it before it totally freezes my Mac again

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Performance: Memory' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 4

[S3V3RIN]

Attachment: Screenshot 2025-12-01 at 3.51.22 PM.png

It doesn't seem like Firefox is taking up too much memory space, but my laptop is really slowing down and I think it's just a matter of time before it freezes and crashes again.