Diễn đàn hỗ trợ Firefox

Been using Firefox for over a decade. But lately is has become so slow now. Often freezes up if more than two tabs are open or a website is in any way very complex. What settings and issues should I check? What has changed? I can run the same sites on Brave and Edge browsers with no issues or not nearly as slow and bogged down.

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.

Hi. Recently, a old issue has comeback on my firefox. When I load youtube video, or a twitch livestream, at 60FPS, and I scroll down the page, the scroll "lags" until the player is off screen. By lags i mean it slows down the scroll and is no longer smooth. This is an issue I've had before and had successfully dealt with by accessing about:config and turning media vp9 off, but it has returned fairly recently, since I do not remember this issue happening before the last week, maybe two. Another issue, also on youtube, is that when I scroll down through shorts, sometimes after a couple of videos, the browser will visually freeze entirely, but will still allow me to click things on the page and also play sounds. After about 20 or so seconds, it will unfreeze and work normally.

I understand that this issue, atleast the 60fps scroll lag, has been an issue for a while and I have tried multiple fixes for it, changing various boolean settings, refreshing firefox, updating my Nvidia drivers to the newest via nvidia app which i should add has never been an issue for the past few months and has worked flawlessly and my nighmarish evening of troubleshooting ended with me completely fully uninstalling firefox and redownloading fresh, but the issue presists.

It should be noted that on other browsers, I have no such issue. Im not sure if mentioning this is some sort of taboo or persona non grata, but i also downloaded and tested Waterfox, and it also does not have this issue. The only band aid fix I found for the moment is that turning off Hardware Acceleration fixes the scroll issue, but it causes awful screen tearing, which is just as bad and distracting.

So to my understanding, 3 potential things are happening. This issue is just in my head Something on my pc is dying and I have a mechanical or software problem Or finally, there is some issue with a recent update, either with firefox or maybe some driver somewhere causing an issue. It just upsets me greatly due to this being a relatively new issue. As stated I have dealt with the scroll lag before and did find a permanent fix, and firefox has since worked literally flawlessly for months/years. But now, somewhere within the last week, maybe 2, something has gone wrong. I hope this gets fixed in an update, or if others have this problem there is a fix. Thank you.

I love Firefox and have used it forever. But its memory usage is killing me lately and I'm seriously reconsidering.... PC, Win11, Intel7, 16GB memory. (I'm typing this from Chrome)

I've updated, restarted, but it keeps maxing out and slowing my computer to a crawl. Somebody please tell me there's a fix pending?

I am using Firefox on my MacOS Tahoe. There is a persistent annoying issue where whenever I close (physically fold) my laptop screen and reopen it, Firefox will be frozen. It will be frozen in the sense that I am unable to interact with any tabs or anything until I manually quit Firefox and reopen it (which automatically reopens all my tabs), making it usable again. This doesn't happen every time I close and reopen my Mac, but it definitely happens the majority of the time and makes the browser hard to use.

I've attached a screenshot of what a new window looks like when Firefox is frozen. It looks just like a Firefox window when unfocused.

Notes:

• It doesn't entirely freeze Firefox. In fact, I can "switch" to a different tab by clicking on the tab and then shutting and reopening my laptop again. The new tab will show on reopening but Firefox will still be frozen. This process can be repeated.
• I can pretty consistently replicate the bug by shutting my laptop, waiting 10 seconds, and reopening it. This will almost always result in the freeze.
• The bug still happens if I'm not focused on the Firefox window but on a different app.
• The bug doesn't seem to happen if I just lock my screen but don't shut it closed.

Things I've tried that haven't fixed it:

• Updating my OS.
• Restarting my laptop.
• Disabling hardware acceleration.
• Disabling themes and extensions.
• Deleting and reinstalling Firefox, including deleting the user data in the "Library/Application Support" folder.

Let me know if there's any more information I can provide or fixes I can try. Also let me know if I should go ahead and file a Firefox bug report for this. Thank you.

Firefox was using GOBS of CPU, so I killed the master process and relaunched, but after launch I couldn't get any pages to finish loading. I then hoped to copy URLs from tabs and paste them into Floorp (which is working fine, as is Chrome), but I couldn't even snag the URLs (dominated by YouTube pages). I ran a full-system virus scan, finding nothing. The most recent Windows-11 update on 2026-Jan-15 isn't recent enough to be a likely causal factor. Firefox has about twice as many extensions as Floorp, but it was running fine until late yesterday (it's now after 3AM). I couldn't get the extensions page to load, so I've attached a screenshot of C:\Users\Mike2\AppData\Roaming\Mozilla\Firefox\Profiles\oa7ou5xk.default-release-1715337056307\extensions There are several other profiles, but there's very little in them (one profile with a times.json & several profiles containing a parent.lock file)

Processor Intel Core i9-9980HK CPU @ 2.40GHz (2.40 GHz) Installed RAM 128 GB System type 64-bit operating system, x64-based processor MSI GT75 Titan 9SG

If I reinstall, will I lose all of my tabs?

Hi, I’ve noticed that Firefox often uses a lot of memory when I have multiple tabs open, even more than Chrome or Edge on the same number of tabs. Sometimes it slows down my system or makes switching between tabs laggy.

Is this normal behavior, or is there a way to reduce Firefox’s RAM usage without losing performance? Are there specific settings, add-ons, or troubleshooting steps I should try?

Thanks in advance!

Version 148 is very slow. When there are 5-10 downloads, other websites won't open. That's why I use version 140. And why are there so many files in the folder - ....profile\storage\permanent\chrome

Firefox has been running incredibly slow. I currently only have this window open, but if I open my task manger it shows 10 Firefox windows running. If I right click and end task, it will end the task, but shortly there after a new one will pop up. 1 of the is running in efficiency mode. I assume this is what is slowing down performance, but I do not know how to fix.

https://www.mlb.com/gameday/braves-vs-nationals/2025/09/17/776286/live

this site at mlb.com or any site showing a live game eventually freezes up and cannot be closed normally. task manager or re-boot is only way out, starting over with a new instance of firefox after ending all firefoxes.

this has been happening just this past few days, after firefox updated to 143.0 on windows 11 using defender, no other screwed up security software.

firefox needs to fix this, it is not likely anything with the site but rather with firefox latest update, as this has always worked before on this same computer.

Dennis Coleman

Hello Firefox Support,

I am experiencing a consistent and disruptive performance issue that occurs immediately after certain complex web pages (particularly those with heavy scripting or dynamic content) have fully loaded.

The symptom is a temporary but complete freeze of the Firefox window, often lasting between 5 to 10 seconds, during which time the browser is completely unresponsive. This freeze is accompanied by a significant spike in CPU usage (often reaching 90-100%, according to Task Manager/Activity Monitor).

Details:

Trigger: The freeze reliably occurs right after the page status changes from "Loading" to "Done." I suspect it is related to post-load scripting execution or rendering finalization.

Impact: Any ongoing user interaction is halted until the spike subsides.

Tested Scenarios: I have replicated this on multiple sites, including heavy news aggregators, social media feeds, and complex web applications.

Troubleshooting: This issue persists even after:

Clearing cache and cookies.

Running Firefox in Safe Mode (disabling all extensions).

Creating a new, clean Firefox profile.

This severely degrades the browsing experience, especially when quickly navigating between tabs or starting a session.

Could you please investigate potential issues within the core rendering engine or script execution scheduler that might be causing these severe post-load processing bottlenecks?

Thank you.

I can complete the sign in and enter my password, and then I get a spinning wheel and can no longer click on the tabs or minimize the window. I have to force close it and it shows as not signed it. I've also tried signing in using my phone and the QR code, same thing. This happens with or without 2FA, I turned it off and the issue persists. Everything else about the browser works completely but I can't sync across devices without the Mozilla login working.

After the version 149, a very strange issue happens to me with Firefox. When I try to log in to some services (Google account, WhatsApp, Mozilla account) the browser freezes. That does not happen if I turn the hardware acceleration off so I essentially thought there is some issue with my graphics drivers which I then updated (Nvidia 580.142 drivers for Geforce GTX 960). But what is very strange is that the issue isn't present when I use Firefox in private mode! That means: Normal mode, HW acceleration on -- freezing Normal mode, HW acceleration off -- not freezing Private mode, HW acceleration on -- not freezing I switched to the ESR version now which works fine too. Still, I am curious about what is going on and I would like to find a solution. My system is fully updated Arch Linux. I cannot share my data since I can't log in to my Mozilla account. Thanks in advance!

im using firefox on ubuntu, version 139.0.4. when i browse the internet using firefox, every some time the toolbar and the search bar "freeze" - i am unable to click anything, from the url, to any of the buttons. it takes up to like 1/2 minutes for the search bar and the toolbar to work again. i never had this issue before, neither on ubuntu (and other linux distributions), nor on windows...

After every update, Firefox starts to a blank screen and will not start loading the webpage url put in for over twenty minutes to a half hour. During this time other browsers on my Win 10 PC load immediately so it is not a network issue. It is Firefox. When I see that an update is pending I hesitate to do the update because I know I will lose the use of Firefox until it is ready to respond. It just hangs with "loading X.com" showing at the bottom left of the blank screen. I have been using Firefox for a long time and in the past year or longer it has become very unreliable. There are also instances where without an update it will do this and the only way I can get it to work is to clear the cache and the history through settings. What is going on with Firefox! (And lately there is an update every couple fo days!