Diễn đàn hỗ trợ Firefox

Hi everyone,

I’ve noticed that Firefox tends to use a lot of memory when I run several browser-based tools at once — especially web calculators or dashboards that update data dynamically.

For example, when I’m testing a lightweight web calculation app (something similar to a gratuity calculator that updates values in real time), Firefox memory usage slowly increases, and sometimes the browser even freezes if multiple tabs are open.

I’ve already tried:

Clearing cache and disabling extensions

Running in Safe Mode

Using hardware acceleration on/off

Still, the problem persists.

So I’d like to ask:

1. Are there any specific settings or flags that can help manage memory usage better for interactive web tools?

2. Does Firefox handle JavaScript-heavy calculations differently compared to Chromium-based browsers?

3. Any recommended performance tweaks for developers testing such tools locally?

Would really appreciate advice from anyone who’s optimized Firefox for this kind of lightweight, web-app testing.

Thanks in advance! 🙏 bold text

OS: Linux Recently, firefox has been annoying me with not closing a tab when I click the X like normal. I have to right click and close it, or press ctrl w. I am unable to move tabs around, as well. I am not sure since when this next bit has been happening, but I am also unable to interact with many elements of the top bar. The only thing of the firefox ui besides the websites themselves that let me interact with them at the moment is the home button, the new tab button, bookmarked sites, and that box icon on the left corner that lets you look at previously closed tabs. My Firefox's version should around, I believe it is 140.5.0 ESR. Thank you in advance. Update: Upon a restart of firefox, it appears to be working again as normal.. However, the bit with tabs not closing when the X is clicked and not being able to move tabs around has been happening multiple previous times, and it may come back. Update again: The issue does come back after some usage. I'm using KDE plasma with Wayland. I will try what the answer asked, and come back later. Update: This seems to happen very randomly and is not reproducible for me.. It will go a few days being fine, then randomly freeze again. Has not happened under another user, at least not yet.

I opened Firefox on one of my computers as usual today but the whole performance changed. Used to go to my home tab and select various news sites to see what was happening. First, when I scroll down the bookmarks, I would hit the "news" and click on it so all the sub items would stay in the scroll, but instead of that, it wanted to open every item as a new tab. When I finally started opening the various news outlets, it opened them in new tabs, it had always opened in the same tab. Then, I couldn't close the various tabs it had opened. I would go to the tab and hit the "X" but it didn't close the tab. I had to use a drop down menu to close a tab. And when in a site, I used the scroll button on the mouse, instead of scrolling, it made the page larger or smaller instead of going up or down. What could make such a change in behavior? I opened up the 'settings' on it and looked at 'tabs' and they were the same as the ones that are on this computer that works as expected. Both computers have it set to open all previous windows and tabs. Both have the same settings for 'tabs' and 'browsing'. I don't get it. Both are version 143.0.3 (64-bit) I have Ubuntu OS.

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.

I normally use Firefox Developer Edition, version 127 because any later version always freezes my whole computer (probably because I'm using a 15-year old PC). Recently all my extensions became disabled. I'm now also unable to install any extension because it says "Installation aborted because the add-on appears to be corrupt". I found some instructions on Mozilla website about deleting compatibility.ini and extensions folder, but it didn't solve the issue. Now I'm stuck and confused as I suspect some of the extension files that should be in my Profile folder may not be there.

The simplest solution in this case would be to use the "Refresh Firefox" option which resets everything to default settings, but every time I do it my computer freezes until rebooted. Uninstalling and reinstalling manually is also not the way to go, because it retains all the settings.

I've tried installing the standard Firefox browser (v. 119) alongside the Developer Edition but the same issue is there as well.

I'm looking for an alternative way to get a clean Firefox install, so I can fix my extensions.

Additional info: - Your system specs? Windows 10 64-bit, 4 GB RAM, Pentium Dual-core, no GPU - Hardware acceleration? Disabled. - Using any mods? Yes, two. Geckium for Firefox, which always works fine. The recent issue started when I played around with Revert8Plus, but it initially worked without issues.

This started happening a few days ago.

I tried to drag a tab out of the main window to put it in its own window on my other monitor, but the tab just became unselectable, and if i scrolled in the tab bar, the tab icon and text would remain locked in place in the display while the other tabs moved behind it.

The main Firefox window also lost the minimize, restore, and close buttons. The only way to make the tabs work was to close Firefox and relaunch it.

I noticed this happened only after any app in the OS went full screen, be it a steam game, or another Firefox window, or a VLC window, or anything else that I did that made an app full screen in any of my monitors.

I am using Ubuntu 24.04 with KDE Plasma 5.27.12. Kernel is 6.14.0-29. Display server is Wayland.

Initially I thought this could be a problem with the snap version of Firefox, so now I've installed the deb package, but the problem remains. Firefox is the only app which presents a problem of any kind when any window goes full screen.

Here's a video showing what the problem looks like, in case my description was not clear. The ghostly tab in this video is the chess.com home page and you can see it as the third tab from the top right of the video, and it remains in that position as i scroll the other tabs, completely unselectable with the mouse.

https://www.youtube.com/watch?v=-mAfPS3_qkg

Any idea of what could be causing this issue to appear?

Thank you!

I have been dealing with an issue in Firefox on Windows 11 for several weeks now hoping for a fix soon but it has not come yet. When I am browsing on eBay, it will lock up and I have to identify the thread in Task Manger and kill it (just the runaway thread, not the entire program). I can then continue of eBay for a short time before it happens again. This only happens on eBay while just browsing, not bidding/buying. Is anyone else having this issue?

A couple days ago, some weird issues have started:

• All my bookmarks are gone
• Any of the buttons in the UI that open a smaller UI do not work (such as the 3 bar menu)
• Similarly, right clicking to open a menu (such as "Save Image") also does not work
• Any dropdown menus in websites seem to also not work. For example, in this very support page, I could not select an option in the "Which topic best describes your question?".

I can't restart and troubleshoot Firefox since I can't access the 3 bar menu.

Warning Unresponsive script, this popup causes many issues as I use many tabs and it will get the popup and the only choice I have is to say continue, that then redirects me to that tab, so what I was doing gets interrupted. I have to go and find the tab I was working in when I may get another popup. I've had it where I've had popup under other popups, I tried the extending the time but that seemed to make things worse.

I need to totally disable that popup, tell me how.

Firefox I'm getting nothing done, Do I really need to use chrome?

When I brought Firefox up about a week ago, it presented me with a survey, results of which were sent to Firefox developers. They asked several multiple choice questions about features, but they didn't ask a very important question: Would you use Firefox more if it used less system memory? I currently use Google Chrome for about 2/3 of my web browsing because Firefox uses up too much system memory. I would prefer to use Firefox most of the time, but can't, since it bogs down when memory usage gets too high.

The survey should have included a text input box so users could enter any comments for the developers, and the survey did NOT do that.

So, after completing the survey, I was disappointed that I couldn't comment on the most important issue I have with Firefox. I would like the Firefox dev team to try get Firefox's use of system memory down. A short while ago, I opened 4 websites in Google Chrome, then opened the exact same 4 websites in Firefox. The attached shows the memory usage of each browser.

I get screen tearing on videos or when i scroll on any website. Only happens on Firefox, I've tested Chrome, Edge, Opera.

https://streamable.com/80gxcm

Smooth Scrolling is Off. Hardware Acceleration is Off. I've tried toggling "gfx.font_rendering.directwrite.force-enabled" Firefox is up to date.

None of this has helped.

Добрый день! Обратил внимание, что с последним обновлением. у меня стала виснуть браузерная строка полностью и я не могу зайти в настройка. Уже было несколько раз так и мне помогает только полный перезапуск браузера.

Я могу прислать видео, как это выглядит.

Прошу помочь решить эту проблему. Спасибо

Hi, After updating to the latest version of Firefox on my laptop, I’ve noticed that the battery drains much faster than before. I haven’t changed any settings, but the browser seems to consume more power even with just a few tabs open.

I’ve already tried:

Restarting my laptop

Disabling unnecessary extensions

Clearing cache

But the issue is still there. Is there any specific setting or workaround to reduce battery usage in the new update?

Thanks in advance!

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?

I used to play World of Tank and look at YouTube on my second screen. Everything went smooth untill this week. YouTube on Firefox on my second screen is lagging or freezing. I tried Opera, I tried Edge it worked fine, but with Firefox, it is no more possible to play YouTube on my second screen while playing. It is not a matter of graphic hardware as this issue only happen with Firefox. I tried to deactivate every module and to reinstall Firefox (either the Beta version) but still got the same lagging and freeze on YouTube. Do you need anything that can help you to investigate this issue, this is really terribly frustrating and boring.

Best regards Patrick / Darkiger

So I've got 6 tabs open in Firefox, all working properly. To help me focus on another task, I open a 2nd window in Firefox. It is, however, blank and unresponsive, doesn't show any extensions in the toolbar, but does show "Firefox View" which I don't normally have showing. I can only close the new window by using Task Manager to shut Firefox down completely or by right-clicking in the Taskbar on the dead window and selecting "close window". What's going on here? First image: working tabs, Second image: unresponsive new window. Regards, Ian Firefox 140.0b2 (64-bit) Windows 10 Pro

Firefox has been using more RAM and CPU on my system recently, especially with only a few tabs open. Is this expected behavior, or are there specific settings, extensions, or configurations I should check to improve performance?

I use a Mac running macOS Sequoia 15.7.2. Each time I attempt to login to https://music.amazon.com, Firefox freezes which then requires me to quit Firefox and restart. Therefore, I need to use another browser to access the site. What is the solution to this issue?

Anyone else having an issue with the newest firefox in Linux Mint? I don't know what's causing it but when multiple tabs open my address bar and all other primary buttons/icons (including the menu button) don't work, only the download button. Across multiple tabs. Not using any groupings/classifications or any "new" tab features or vertical windows etc.

Ubuntu - I use the SNAP version of Firefox - I generally have lots of tabs open but only use 5 or so of them and it's generally fine.... but when I am closing Firefox, it USES like 100% of the CPU and ALL of the RAM and ALL of the SWAP memory when closing.

This locks up the computer.

Sometimes it doesn't quite go all the way but I can watch it all happen in real time, using Task Manager - and that shows a solidwall of all resources occouring, when the close Firefox is run.

I am told by research via ChatGPT that this is a very real problem with the SNAP version and it's best to change to the Debian version, copy all the bookmarks etc., across and then uninstall the SNAP version.

It's rather disconcerting to have Linux crash because of this one app locking it up and frequently.

Chat GPT:

Is there a problem with Firefox Snap Version closing and using all the resources while doing so, which results in locking up the computer?

You're definitely not imagining it—there have been reports of Firefox's Snap version consuming excessive system resources (CPU, memory) and even causing lockups or hangs, particularly during closure. Here's what’s going on and how to mitigate it:

What’s Happening with Firefox Snap?

2. Browser Hangs or Locks the System on Close

On Linux (especially Ubuntu), users have reported that closing Firefox can lead to it hanging in memory, sometimes unresponsive and still consuming resources.
Super User
Ask Ubuntu
A stark example from Reddit illustrates the severity:
“About 50% of the time I open Firefox, it'll reach 100% CPU usage in about 30 seconds… PC completely unusable unless I shutdown.”
Reddit

3. Known Wayland Sway Bug

On Wayland/Sway setups, reloading Sway while Firefox is open can trigger intense logging, causing high CPU use and an enormous syslog.
Fix: Set MOZ_DISABLE_WAYLAND_PROXY=1, or upgrade to FF 125 where the issue is addressed.
Reddit+1

Alternative Approach

Many users, particularly on Ubuntu, opt out of Snap completely in favor of the .deb package or PPA builds. These alternatives often avoid these specific issues. Ask Ubuntu Reddit

Thoughts? Solutions?

Thanks in advance.