Firefox Community Forum

Ubuntu - I use the SNAP version of Firefox - I generally have lots of tabs open but only use 5 or so of them and it's generally fine.... but when I am closing Firefox, it USES like 100% of the CPU and ALL of the RAM and ALL of the SWAP memory when closing.

This locks up the computer.

Sometimes it doesn't quite go all the way but I can watch it all happen in real time, using Task Manager - and that shows a solidwall of all resources occouring, when the close Firefox is run.

I am told by research via ChatGPT that this is a very real problem with the SNAP version and it's best to change to the Debian version, copy all the bookmarks etc., across and then uninstall the SNAP version.

It's rather disconcerting to have Linux crash because of this one app locking it up and frequently.

Chat GPT:

Is there a problem with Firefox Snap Version closing and using all the resources while doing so, which results in locking up the computer?

You're definitely not imagining it—there have been reports of Firefox's Snap version consuming excessive system resources (CPU, memory) and even causing lockups or hangs, particularly during closure. Here's what’s going on and how to mitigate it:

What’s Happening with Firefox Snap?

2. Browser Hangs or Locks the System on Close

On Linux (especially Ubuntu), users have reported that closing Firefox can lead to it hanging in memory, sometimes unresponsive and still consuming resources.
Super User
Ask Ubuntu
A stark example from Reddit illustrates the severity:
“About 50% of the time I open Firefox, it'll reach 100% CPU usage in about 30 seconds… PC completely unusable unless I shutdown.”
Reddit

3. Known Wayland Sway Bug

On Wayland/Sway setups, reloading Sway while Firefox is open can trigger intense logging, causing high CPU use and an enormous syslog.
Fix: Set MOZ_DISABLE_WAYLAND_PROXY=1, or upgrade to FF 125 where the issue is addressed.
Reddit+1

Alternative Approach

Many users, particularly on Ubuntu, opt out of Snap completely in favor of the .deb package or PPA builds. These alternatives often avoid these specific issues. Ask Ubuntu Reddit

Thoughts? Solutions?

Thanks in advance.

I had two Firefox windows on my computer, one with a few tabs of Youtube and Twitch pages, and a private window with a single Twitch stream. I've had them and the program open for days, with my conputer turned on and off multiple times with no issues.

Today I booted a game I installed yesterday on my computer and played for a few hours, after closing the game, both my Firefox windows became completely inaccessible.

I've tried closing firefox, restarting my computer, letting Firefox create a new xulstore file and nothing has worked. I can't see the window, I can't make it active. It's permanently minimised.

It spikes Desktops Windows Manager to 100% GPU usage, it makes my PC lag and run slow, and I can't do anything in the browser cause the window won't stay open or up. I can't even open the old window and then a new one, it stays minimised and I can only see the preview by hovering my mouse over it.

I've tried GPU driver updates, I tried anti virus scanning, and I've tried opening another browser which did work. But Firefox is the one with all my saved settings and preferred browser. I also can't see the Firefox window at all when using the window key + TAB to check my desktop, but it does show up on Task Manager as running.

Please help me restore my program. I'm making this on my phones firefox browser which is running fine

Firefox not responding on macbook M4 Macos Tahoe 26.0 I tried restarting Firefox I tried restarting my macbook But everything repeats. Use Firefox for a while and it freezes again. Tôi sử dụng Firefox mới nhất: 143.0.1

My internet browsing gradually gets slower over time. By the end of a day or a couple of days, it is unusable. The problem isn't bandwidth. A speed test shows that throughput is absolutely normal. It's the browser response to navigation. ie clicking a link, typing a URL into address bar, etc. and having to wait minutes for the page to start loading.

If I quit the browser and re-open, everything goes back to normal.

Any ideas what might be the problem?

Just a note that I had a lot of probem with the firefox not opening when a link is being clicked. It would open in background but not come to focus.

External hyperlinks do not open in Firefox window.

I found that focusmanager.testmode was the cuplrit, after a lot of hard work.

Using Google Voice became unusable. Firefox too slow. Had been running just fine up till maybe a month ago when I finally gave in and allowed Firefox to update. Not knowing if it was a Windows or other issue I stupidly did a Windows reset and lost all my installed programs (including Firefox). I did a fresh install of Firefox and manually reentered passwords and bookmarks.

Ran fine for a day or two and is now again unusable. Cleared cache and appears to work OK at the moment but still sluggish.

Finn

So, I was downloading some Patreon stuff and Patreon isnt well optimized for browsing older posts. When you have to load multiple more pages dating backwards it slows down the Firefox quite a lot, pretty much to the point when the Firefox reach non-responding state in worst cases.

But luckily for me Patreon worked fine for me tonight, just when I was closing the Firefox, it took like 5 seconds for it to close.

I spent some short time by responding messages on Steam and Discord and then I started new Firefox window, this time I went on Netflix and when the page loaded my monitor went black and then after like few seconds it returned back with "Displayport" message on the top left corner.

When I checked Event viewer, there is nothing at all. When I checked about:crashes, there is also nothing.

Any idea what was that and how to prevent that?

It takes almost a minute for my home page to come on after I click on My Firefox icon. That has only started happening in the last week or so. But . . . also . . . when I sign into my email account with my ID and complete password, even though I check the "stay signed in" box, that does not happen. I need to fully sign in each time, and that, too, time-wise is somehow related to the delay in getting my home page up. On several occasions I have gotten a message that Firefox is not responding. Thanks for any help you can give. I have Windows 11.

Since this week's update of Firefox Developer edition when the browser is restarted tabs do not load until I reset the browser.

I suspect an add-on but have not been able to determine which one.

This is happening on multiple (3) physical computers.

I just started a new work role and haven't been able to find the time to troubleshooting of the issue myself.

This has been very disrupting and stressful.

Several weeks ago Firefox worked normally for me. I left for most of the day and when I got home Firefox no longer worked at all. Everything on my home page was gone and when I typed in websites - such as my e-mail program or Facebook, nothing ever came up. I'm not super browser savvy, but I opened the menu and under help was "trouble shooting mode". I didn't know what that was but figured nothing much more could go wrong with Firefox, so I chose that. I had to rebuild the websites I had in a row on the middle of the page. I didn't lose bookmarks, but everything else was different. So I left it that way.

Earlier today, Firefox wanted me to do another update. I thought maybe by agreeing to that, things might return to normal. Noooooooo. It's no better whatever. Now I don't know how to get out of troubleshooting mode to know if anything will work normally again.

I am seriously considering switching browsers, but I have a LOT of stuff bookmarked and that would be very intensive to build all those book marks in another browser.

Firefox occasionally stalls during a page load or refresh. A quit/start sequence of Firefox resolves the stall without further action. Is there a key sequence that invokes a restart: Firefox 140.0.2 (aarch64), MacOS 15.5 (24F74)

Hello For some reason most of the buttons in my toolbar have stopped working. When I first open Firefox they all work, then when I enter websites they stop working. The 'home' button still seems to work, but almost all others (such as the 'back' button etc) can't be selected. This is very frustrating. To note, I am not tech savvy at all.

Thank you in advance for your help.

Andrew

I am using a new Windows 11 computer. I use Firefox for almost everything. But it opens many processes and it very quickly gets to the point where anything I do causes a hang. If I am listening to music or a podcast it pauses and buzzes. This AM I turned on the computer and opened Firefox, without reopening an old session. I had open two windows with two tabs in each window. Using Windows Task Manager I determined that Firefox has twenty-one processes open. Some of them have the efficiency leaf and some do not. I do not use an Add-On manager, but use MalWareBytes for a VPN and protection. Please help.

A couple days ago, some weird issues have started:

• All my bookmarks are gone
• Any of the buttons in the UI that open a smaller UI do not work (such as the 3 bar menu)
• Similarly, right clicking to open a menu (such as "Save Image") also does not work
• Any dropdown menus in websites seem to also not work. For example, in this very support page, I could not select an option in the "Which topic best describes your question?".

I can't restart and troubleshoot Firefox since I can't access the 3 bar menu.

This problem just began today on my Win 11 laptop. Firefox is current - 139.0.4. Win 11 is current. No new software has been installed. Firefox hangs up and will not move. Task manager shows FF is consuming more than 90% of my 16GB memory. I must end the FF task to get up and running again.