Firefox コミュニティフォーラム

Hello Community,

I have been experiencing significant issues with Firefox for the past couple of months. The main concern is high CPU and RAM consumption during video playback, especially on YouTube.

This issue started appearing only for the past month or two; it was never present before on the same system, and no significant hardware changes have been made.

Crucially, this problem is exclusive to Firefox. I have tested video playback on other browsers such as Google Chrome, Brave, and Microsoft Edge, and do not face any similar performance issues with them.

Your assistance in resolving this is greatly appreciated.

Thank you.

Hi everyone,

I’ve been using Firefox as my primary browser and overall it works great, but I’ve noticed a slowdown pattern during longer sessions and wanted to compare notes with the community.

After running the browser for several hours with many tabs open, I sometimes see delayed responses when switching tabs, typing in text fields, or opening menus. Nothing crashes, but the interface feels heavier until I restart the browser. Once restarted, performance goes back to normal.

I’ve already tried reviewing extensions, disabling a few that I don’t use often, and checking memory usage in about:performance. The numbers go up as expected with more tabs, but I’m not sure how to judge what is considered normal versus problematic.

Because the issue improves after restart, I’m wondering whether this is typical resource buildup, session handling, or something specific I should be tuning.

How do experienced users usually approach diagnosing gradual slowdowns like this? Are there particular indicators in the built-in tools that suggest a real problem rather than expected behavior?

While reading more about how browsers manage memory over time, I found this general explanation helpful for understanding the bigger picture:

I have recently begun to have hard 'hangs' while attempting to view a video on a site I'm already connected to. I've tried to overcome these hangs, but they continue to happen even after firefox has been in use for a short time. I have to restart my computer, since the hang is locking up all control input.

opening firefox why is it blank page. When I open up FireFox the page is Blanck the account tab top right dosent work nothing works no search just blank page why is that. Yesterday it was fine worked

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)

Roblox was blocked on my device and I wanted to get it unblocked and play it on Infrexa with Firefox. I already followed steps mentioned on the official webpage: https://www.infrexa.com/now-gg-roblox-login-and-play-roblox-unblocked-on-your-browser so please don't advise similar troubleshooting methods.

Now I am able to play roblox but the problem is that when I play the Roblox through "Mozilla Firefox" it shows an error "Firefox is already running but is not responding" and then becomes unresponsive when pressing refresh button, the fan gets faster and device heats up with too much hanging. But when I open the Roblox through "Chrome" it comparatively works good and asks for login details and after redirection it allows me to play Roblox Unblocked without any issue. "Roblox unblocked" here simply means a technical sense, meaning “not crashing” or “free from software or network errors and or browser malfunction".

I have been using Firefox for a long time and my passwords and user ids are saved in the browser so I want to continue using "Firefox" as default browser but I am having the issue in playing roblox unblocked and other games through Firefox browser. I think the current issue that I have started facing is especially after a recent windows update.

I also tried many other gaming platforms like Official Roblox.com, Now.gg Roblox, easyfun.gg and web.cloudmoonapp.com but all of them faced same issues on Firefox while running ok on Chrome.

I am currently running Windows 11 (25H2 Licensed version). I want to play roblox unblocked on my device using Firefox (updated). My parents have already allowed me to play Roblox and I am playing it on my own device and internet connection. Please fix the browser issue and unblock Roblox for me. Please also check my browser version against Windows 11 compatibility if possible.

If you fix this issue for me, I will be grateful to you.

On my steam deck, from time to time, the firefox's touchscreen support seems to switch modes.

The symptoms are:

- Instead of scrolling, one-finger touch-and-drag now zooms in and out (depending on direction)
- The touchscreen no longer lets me select or close tabs, or focus or click in-page widgets
- This mode-switch is restricted to the firefox window in which it happens
  - Moving the tab to a new window results in the new window working fine
  - Other existing windows are unaffected (although they may later experience a touch mode switch  event)

I have yet to determine what triggers this switch, nor can I figure out how to undo it.

The browser is very slow when opening a new tab... When I've opened Youtube it says that the Page is slowing down the browser and it takes a very long time to respond... I'm using MacOs Monterey 12.7.6 and I believe my Firefox is up to date

I'm listening music from youtube and playing Guild Wars 2 in the same time. Tell me pls bc I think it's unnormal, why I see in task manager that Firefox is opened 12-17 times?...

On my Windows 11 IOT Enterprise LTSC system firefox does not entirely close. After I installed my professional tax software from Drake Software LLC the following happens repeatedly: I open Firefox, look at a page, close Firefox, the screen clears and when I try to REOPEN firefox a popup says that it is still running and offers close or cancel. Neither button opens,closes or cancels Firefox. I have to reboot to make Firefox (147.02 64bit) close. This happens every time I open Firefox.

I often keep many tabs open for research, and Firefox memory usage grows significantly over time. Are there practical settings or habits that help manage memory without sacrificing usability?

Hi there, each time I run firefox, a new firefox icon like the attached picture shows up. Now there are several of them. This starts to crowd the dock, also I'm not sure why they are there because I already have a firefox icon in the main dock. Also they are not windows of a firefox window. Clicking on them does nothing.

Every 5-10minints I get white screen for 2 to 30sec when I use the firefox browser. I have tryed the varius advice avelebel , it does not help My computer: Enhedsnavn DESKTOP-KN6DEV0 Processor Intel(R) Xeon(R) CPU E5-1620 v2 @ 3.70GHz 3.70 GHz Installeret RAM 32,0 GB Lager 932 GB HDD ST1000DM010-2EP102, 224 GB SSD INTENSO SSD Grafikkort NVIDIA Quadro K2200 (4 GB) Enheds-id 734915BD-7D9F-484B-B52B-2BD44CFC0F0C Produkt-id 00330-80000-00000-AA837 Systemtype 64-bit operativsystem, x64-baseret processor Pen og touch Denne skærm understøtter ikke input via pen og touchinput Windows

Udgave Windows 10 Pro Version 22H2 Installeret d. ‎10-‎01-‎2026 Operativsystemets build 19045.6466

I have Adgaurd and stop of autoplay. Hope you can help Best regards Kristian

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!

When i start fire fox it immediately opens 10 additional versions in the background which I can see in task manager and they take up a lot off memory. If i end task them they immediately come back. This only started recently. I noticed it because now when i open say a youtube video it shows it as number 4. This never happened before unless I had the same video open more than once.

If I can not stop this I will have to uninstall.