Gmail and slack tabs are real monsters, yeah. My one slack tab for work will easily eat up a gig of ram over the course of a day (or less), and gmail tabs work up an appetite too. Twitter is also bad and I've occasionally seen a twitter tab eat up a gigabyte. I still run Slack in a Firefox tab though, since the native Slack.exe client has a habit of allocating 40GB of heap and paging out all my other applications.

It periodically gets worse when site authors make changes, and in practice a lot of these are site bugs. I file reports on Bugzilla when I see FF leaking memory on these sites and it usually doesn't turn out to be an FF bug. Maybe worth making reports on bugzilla though, the team is very responsive and they might be able to figure out a workaround for its memory usage in your scenario.

If and when there's time, I'll have to reach out. I can't imagine a world in which anything running on my laptop needs 40GB of heap allocated. I've only run the Slack desktop app once or twice though. Felt like a beast even then.

Is the OOM problem still there even after Quantum release? This was the main turn off factor for me with FF long ago, and when the OOM fails to even trigger, the famous swap thrashing occurs.

I tried again with Quantum, but then there were still stability problems causing the whole browser to lock up (just like Edge. But same problem existed in FF since long ago too), so I've never tried it anymore since then. Twice bitten, thrice shy.

Yes. My laptop is a Xeon with 32GB RAM and I can't keep FF alive for more than 4-6 hours. I let upstream (ubuntu) keep packages updated so I'm current.

That is... puzzling. I use Firefox on a 2GB Thinkpad T42p, regularly have 100+ tabs 'open' (as in 'opened in the background' which means it'll start rendering when I actually open the tab) over 2 or 3 active windows and I have never seen it being killed by the OOM killer. It can crawl due to paging but it does not get killed. To me this sounds like you should either add a bit of swap space or tune the OOM killer to be less trigger-happy.

If they’re having OOM problems, especially with 32GB of RAM, I’d expect it to start thrashing the swap as it does mine on my Ubuntu box. As much as I like FF, it is not consistent across hardware/OS setups and I imagine it makes it rather difficult for Mozilla to debug as this has been an ongoing problem for years at this point.

More likely there is no swap space defined so that any memory error will trigger the OOM killer.

Something's terribly wrong there. I'm using Firefox on a laptop with 8GB RAM and hundreds of open tabs. Chromium is unusable with just dozens of tabs due to maxing the available RAM; Firefox just slows down a lot after reaching something around a thousand (and it depends on the version - it's periodically getting better or worse at handling such amount of tabs), but no RAM issues whatsoever.

Are you using any addons that might cause that mem usage?

I am a tab junky (regularly > 200+ tabs, sometimes 1000+) and Firefox never died, and it is used on a laptop that has also IntelliJ + java apps which use quite a big chunk of memory.

You might consider reducing number of processes used by Firefox, I set it to 3 even when I have 4 cores available, it helps reduce memory usage.

Linux with 16GB of RAM.

Nothing much. The biggest consumer could be tampermonkey but the last script I was using has been disabled for a while. I am using multiple profiles though, which could be a problem. My non primary provide gets reaped more than the primary. I'll try cutting down the number of cores it can use and see if that does anything.

What's the use case for 1000+ tabs? Just curious.

It's like temporary bookmark really - something that I want to read today.

I just don't close tabs that often as I should, I forget I wanted to read or I get distracted etc.

And I don't force close tabs when closing the browser.

If Firefox is using an unexpected amount of RAM, report a bug by following the steps below:

1. Open about:memory?verbose in a new tab.

2. Click Measure and save...

3. Attach the memory report to a new bug: https://bugzilla.mozilla.org/enter_bug.cgi?product=Core&comp...

4. Paste your about:support info (Click "Copy text to clipboard") to your bug.

> If you are experiencing a bug, the best way to ensure that something can be done about your bug is to report it in Bugzilla. This might seem a little bit intimidating for somebody who is new to bug reporting, but Mozillians are really nice! http://dblohm7.ca/blog/2014/08/14/diffusion-of-responsibilit...

Oh man, I've having the opposite problem. I recently switched and no crashes yet (Chrome would freeze and die fairly frequently), but good god is FF a memory hog. I've got 5 tabs open, only text (some short programming docs and HN), and it's eating 3.5GB.

Chrome would reach about 150 MB a tab, in my experience.

I have plenty of memory to spare, but still.