Firefox Community Forum

An 8 second delay when I open Firefox for the first time.. Once it has been opened once, it reopens immediately when required. The problem has been present since I installed Linux Mint 9 months ago, Linux Mint 22.2 then, since upgraded to 22.3 Zena. I can live with it, but it is very frustrating! I have tried the obvious things like removing extensions, but I suspect it is a "Linux" connectivity problem rather than a "Mozilla" problem.

Dear Support,

Firefox exhibits significant performance and usability issues related to its cookie and data storage management. Despite implementing ad blocker extensions, the browser remains saturated with cookies and persistent advertisements. Regularly clearing browsing data and cookies is necessary; however, navigating to the settings menu is time-consuming. I recommend developing a browser widget that facilitates rapid data clearing directly from the toolbar or frame. Additionally, implementing a session-saving feature to preserve a set of pinned tabs upon closing and reopening the browser would enhance workflow efficiency, allowing for a quick start with a predefined workspace.

This is all happening while using it for simple tasks like search or copying a text.

Furthermore, the browser experiences severe performance degradation when utilizing certain web applications, such as Kapwing for video editing. Since uninstalling Vivaldi, I am considering migrating to an alternative browser due to these issues. Tasks that typically require one minute are now prolonged to hours, as the browser intermittently becomes unresponsive, effectively limiting usability. This sluggishness persists even after system restarts, with CPU utilization reaching approximately 50%, as detailed in the attached performance report. Notably, I encountered a significant delay—up to an hour—to correct a single spelling error or open a new tab, indicative of underlying performance bottlenecks.

Please address these issues to improve browser stability and usability.

Estimator Just tell me how long this is probably gonna take: 4 to 16 hours. Not kidding!

My Dell Precision Laptop from 2019 runs a frequently updated Ubuntu 24.04. About one or two weeks ago, after one of the latest Firefox updates, i noticed that video streaming produces rectangular flickering in rapid sweeps. ( Also fast scrolling large text websites produces similar flickering, I think I would have noticed it before...) . If you detected it once, you see it always again... :-( First I fiddled around with the nvidia settings because the driver was also recently updated, without much success. Playing locally stored videos, e.g. with VLC media player, still works fine, so the nvidia driver is not the problem i think. Yesterday I installed Chromium and the video performance is fine! As good as with firefox some weeks ago! So it must be one of the latest updates, that causes the problem. Generally I like firefox more than chromium. I like the control you have, e.g. via Add ons.. So I hope that the firefox performance will increase again... Thank you for firefox! Florian Mengedoht

Is anyone looking into this? I found an article that told me to remove some cash files and it seemed to fix the issue but it continues to reoccur. Some apps such as MS360 Outlook seem to trigger it, but if it was truly just a corrupt cache issue then cleaning the cash/profile once should have fixed the issue. Instead its become a constant pain in the *** and I'm tempted to find another browser. Seems very recent as well as I've never had issues with firefox before.

Ubuntu 24 Mozilla Firefox 151.0.3

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.

• • 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

Anyway to fix the issue?

Name: Firefox Version: 150.0.1 Build ID: 20260427221700 Distribution ID: canonical-002 User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:150.0) Gecko/20100101 Firefox/150.0 OS: Linux 6.8.0-111-generic #111~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Apr 14 17:13:45 UTC OS Theme: Yaru / Yaru Multiprocess Windows: 1/1 Fission Windows: 1/1 Enabled by default Remote Processes: 11 Enterprise Policies: Inactive Google Location Service Key: Found Google Safebrowsing Key: Found Mozilla Location Service Key: Missing Safe Mode: false Memory Size (RAM): 31.1 GB Disk Space Available: 383 GB

FIREFOX ... MMMMMMMMMMMMMMMMOOOOOOOOOOOOOOOOORRRRRRRRREEEEEEEEEEE THAN 16 GIGABYTES WITH ONLY 4 TABS OPENED. AND OF COURSE .... BROWSER FREEZES, NEED TO KILL FIREFOX TO STAR WORKING AGAIN ....

WHAT ARE YOU SMOKING THESE DAYS?

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?

Arch Linux Wayland FF v150 from Arch repos

When right clicking the context menu appears, but sometimes in odd places, and the disappears, so you can't select anything.

Same is true selecting the Help submenu from the Hamburger menu.

Restarting the browser fixes it for a few minutes, then same problem comes back.

Other people also reporting the same thing - also Linux Wayland: https://www.reddit.com/r/firefox/comments/1suounc/comment/oi7jk9u/

suse linux 15.6 firefox 140.9.0esr (64-bit)

An aggressive website can cause "isolated web co" processes to be started. When they hog all processors and memory, the computer besomes unresponsive. Keyboard and mouse freezes up.

Is there a way to limit firefox processes to n-1 processors, leaving 1 processor available for me to kill it ?

In 2024-25 Microsoft Edge gained the ability to limit the usage of physical RAM that the processes uses. Once that limit is reached tabs are put to sleep or are unloaded. So a user of Microsoft Edge could restrict the memory usage to say 1GB or 2GB or 3GB and so on till the maximum available physical RAM.

Does Firefox have such an ability? Is there some flag or settings in about:config that can be enabled for a similar feature to be used? Does Firefox have ability to put tabs to sleep once SWAP is started to be used? Is there some flag or settings in about:config that can be enabled for a similar feature to be used?

If none of one of the above is not available with Firefox then will Firefox add this feature as part of the browser in the future?

Since a while, I think it is since I created an extra testprofile with "firefox-esr -P", but I've set my main profile as default again

When opening a link in another program than firefox I get always: a popup "Close Firefox" "Firefox is already running, but is not responding. To use Firefox, you must first close the existing Firefox process, restart your device, or use a different profile."

I do have both firefox and firefox esr, I usually use regular firefox the second came with the debian 13 repository.

I keep the esr to test display issues for reproducibility on my personal desktop, because I manage debian 13 kiosk-style desktops with firefox-esr.

(I noticed also that the regular firefox profiles can not be opened in firefox esr, so I use an extra profile for esr)