Firefox Community Forum

I am on a new PC with Windows 11, using 4 monitors. I keep trying to figure out what is making my mouse and sometimes the keyboard behave sluggish (freezes for a moment). I have takes all suggestions that AI has suggested but it is still happening. Do you have any thing for me to try? It appears to be only when Firefox is running.

How do I roll back an update that is not working on my system? I am very displeased with Firefox overall. You are a memory hog and no settings that I try help. Now, when I open a new tab Firefox freezes and I often have to close and restart, sometimes more than once. You are pushing me away from your product. I am now looking for a browser that is user friendly and compatible with my older computer (windows 10 is the most upgraded OS I can use). I hope to hear from you with a resolution soon.

When my system slows down and takes forever to download, I go to task manager and find 15-20 entries for Firefox when I have only 1 or 2 pages open. Why are they continuing to pile up and slow down my machine and how do I stop it from happening?

After latest update Firefox Developer Edition 151.0 Beta 4 I noticed much slower website loading while using few containers at the same time and overall more lag. Before the update everything was great and smooth I hope it's gonna get fixed soon.

Firefox dropdowns, menus and popup menus do not appear after resume from suspend on Ubuntu 22 or 24 This has been happening for only the last few weeks. Even dropdowns on web pages do not appear. I can click the dropdown and cursor down then hit ENTER to change a dropdown's value but I cannot see anything while I'm doing it. On the menus, I can use hotkeys if I remember them but the menus themselves do not appear. Right-clicking to get a context menu also does nothing but it behaves like it did. If I right click something, nothing changes on screen but if I then click another link or button, the first click is swallowed to dismiss the non-existent popup.

Other apps on the system work fine including Chromium browser.

This only occurs if I start Firefox then suspend the machine and then resume from suspend. After resume, the menus, dropdowns and popups no longer appear.

I am running Ubuntu 24.04.4 LTS on a Dell Optiplex 3050, Core i3-7100x4 , 16 GB ram, Intel HD graphics 630 (KBL GT2), Gnome 46, Wayland windowing system.

I tried Firefox safe mode, clearing the caches, etc. Nothing worked.

Hello there,

I’m experiencing high memory and CPU usage in Firefox, which is affecting my computer’s performance. One issue appears to be that “FirefoxCP Isolated Web Content” continues running even when tabs are inactive, contributing to increased resource usage.

Other browsers, such as Microsoft Edge, reduce memory and energy consumption by putting inactive tabs into sleep mode after a period of inactivity. I would prefer to continue using Firefox as my default browser, but I need a way to manage this level of resource usage.

Could you please advise whether Firefox offers a comparable setting, workaround, or planned improvement to reduce CPU and memory usage from inactive tabs?

Thanks for your help!

• • Background:**

I'm a senior software engineer running Firefox Developer Edition on a Linux machine with 8GB RAM. I have Fission architecture (site isolation) enabled, which I understand is now the default since Firefox 95+.

• • The problem:**

When I open 20 or more tabs across different domains, Firefox's memory consumption scales dramatically — often reaching 4–6GB of RAM for what should be lightweight browsing sessions. This is significantly higher than what I observed before Fission was enabled.

• • What I've already tried:**

- Disabled hardware acceleration → no significant improvement - Set browser.tabs.unloadOnLowMemory to true → partial relief

 but tabs reload constantly, disrupting workflow

- Reduced content.notify.interval → marginal improvement - Tested with all extensions disabled (safe mode) → RAM usage

 still high, confirming it's not extension-related

- Checked about:memory → large number of separate

 "Web Content" processes, one per origin as expected with Fission

• • What I'm trying to understand:**

1. Is there a way to set a maximum process count cap for Fission

  without fully disabling site isolation? I found 
  dom.ipc.processCount but changing it doesn't seem to affect 
  Fission's per-origin process spawning behavior.

2. Is browser.tabs.min-warm-process-count a relevant setting here

  and what is the safe range to modify it?

3. Does Firefox have a built-in memory pressure threshold where

  it automatically consolidates processes — similar to Chrome's 
  memory saver — and if so, which about:config keys control it?

• • Environment:**

- Firefox Developer Edition 151.0b10 - OS: Ubuntu 24.04 LTS - RAM: 8GB - Fission enabled: confirmed via about:support - Extensions: disabled for testing

I recently upgraded from Ubuntu 24.04 to 26.04, using Mate Desktop and Compiz compositor. I am using Firefox from the Mozilla Team PPA, currently 150.0.1. I am running custom kernel built from upstream source, currently 6.18.25. Hardware is a home brew CoffeeLake machine, i7-9700k, 64G of RAM, 2TB WD Black SSD and many TB's of spinning rust, graphics is Intel ARC B50 Pro, ASUS XONAR SE 5.1 Channel 192kHz/24-bit Hi-Res 116dB SNR PCIe Gaming Sound Card. Prior to upgrading Firefox was not 100% occasionally tabs would wedge, now if I get two hours I'm doing good, I've tried disabling extensions and plugins no help. Tried with and without hardware decoding, worse without but bad no matter. Any suggestions how to get stability back?

I'm using v151.0 on Windows 10. The title bar disappears at random intervals and I have to close the application using Alt F4 and relaunch to restore it. I think the menu might disappear too. Otherwise I could close use File -> Exit.

I log in get a dead home window cannot delete , no response to cursor have to use task bar icon to overlay dead home screen. when return to home scree I get the dead old window and use task bar icon to get live home screen to continue. The dead home screen appears and have to select firefox from task bar each time.

After installing Firefox 150, clicking on a window for a different application does not make that application active. Firefox is not letting me leave! I can switch by going to the sidebar and choosing a different application. None of the other applications exhibit this behavior. MacOS 26.3.1

Hi,

I am using macbook pro latest one, and when I use firefox and scroll down from my wireless Mouse to the bottom of the page, the scroll bar jumps to the top while working, is there a fix for this.

Thanks