Firefox Community Forum

Firefox is using disproportionate amount of cpu and memory after upgrade of win 11. How do I fix this. I have an I9 Processor with lots or ram and ssd drives way out of line..

Hi, I’ve been experiencing slow startup times in Firefox, especially when I have my Time calculator web app open. The browser takes longer to load and sometimes becomes unresponsive.

I’ve tried disabling extensions and changing my home page, but the issue persists. Are there any specific settings or troubleshooting steps in Firefox that can help improve performance when using online calculators like this?

Any guidance or tips would be greatly appreciated. Thanks!

my machine is frequently freezingfor windows 11. At first installation is done it is very super and runs the videos which i liked. now it is very slow and video strucking

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.

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've been using Tabliss on Firefox without any issues, but immediately after updating to Firefox 151.0, a frustrating new loading delay started happening.

Prior to the update, new tabs loaded instantly. Now, whenever I open a new tab, the page sits on a completely blank screen for about 2 seconds before the Tabliss layout, background image, and widgets finally pop in.

Because this issue did not exist at all before version 151.0, it seems like the latest browser update changed how extension-based new tabs are cached or initialized, causing a new rendering bottleneck.

My question is a very obvious one if you look at the two screenshots I've attached. The 'X' to close the Firefox browser keeps disappearing, along with the 'maximize' and 'minimize' options as well. This has been happening for months. The recurrence rate is 50/50 each time I open the FF browser. It's not just an issue with closing or minimizing a page, it also removes the access to my Windows taskbar at the bottom!! Normally, when I move my mouse to the bottom, my taskbar pops up and I can access whatever I need, BUT when the FF browser has NO 'X' at the top corner, my taskbar won't show up at all! This is finally getting on my last nerve!🤦♀

Any knowledge as to why this keeps happening?🤷♀

My FF browser is up to date, as of yesterday. My default search engine is google. My PC is still running Windows 10.....could this be the problem?

I was doing some work, when suddenly everything slowed, I checked my Activity Monitor, and it showed Firefox at nearly 20 Gigs of RAM & about 30% of CPU usage! I opened the Task Manager, and it only showed Firefox using 2 Gigs, and 25% of CPU. After a few minutes, the memory usage just as suddenly dropped down to the 2 Gigs as shown in Task Manager, and things seemed to be back to normal.

Why did this happen? I did nothing that would cause a spike, didn't open any new videos, or other high memory usage pages, or applications. I have seen FF showing a similar 20 Gigs of RAM usage, slowing everything down, several times recently, and wonder what could be causing these sudden spikes.

Hi there,

I am on a MacBook Air M3/8GB ram. I was really wanting to use Firefox due to your stance on privacy, etc. but here is my experience:

Yes, I keep a lot of tabs open - I do try to group them and hope that tabs in closed groups are deactivated, but I don't know this at all.

If I use Firefox all will seem well until my machine sleeps. On waking, it is excruciatingly slow - we are talking multiple seconds to even switch tabs or get the cursor to be "hot" when filling a form. Upon trying to quit (restarting being the usual first step), FF will ask confirmation and then close the windows, but will not completely quit, requiring me to force-quit. On restart it seems to behave again, at least for a while.

While I do see some evidence that others have this issue (memory leak?) there are no real methods or answers as to how, if at all, to fix this. It took a lot to get everything on FF working the way I like after leaving Chrome, but I really can't deal with this, and I think I will be looking at switching again - I guess to Safari.

I would love to know how to fix this, but really I don't imagine this is due to my system as much as the FF browser. That said, if you ahve any ideas, I would be open.

I get REAL tired by the amount of resources Firefox eats up with each open window. For whatever reason, having multiple windows open prevents Facebook from loading. I'll get 1 story and a "shorts" bar but THAT'S IT. Even clicking the story to rate or comment does nothing. If I start to delete windows; it will decrease the memory usage and then it will open.

However, I DO NOT WANT TO CLOSE MY WINDOWS IN ORDER TO OPEN FACEBOOK! Firefox should not be eating up that many resources. The open windows are of text and/or picture archives. There is no sound or video playing in the multiple windows open. My system literally has 128 gigs of ram memory so it seems very odd to me that Firefox is using between 11-13% with nothing running in the 15 windows I have open.

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.

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.

• • 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

Gentlemen, isn't your browser using a lot of RAM? I've been freaking out about it in recent years. That's only with 25 tabs open!! Despite the fact that the system was installed just a day ago, without any tweaks!!!