I-Firefox Community Forum

I have a HUGE problem with Firefox memory usage. Some open instances of firefox are taking anywhere from 600mb to 2.8gb of memory. Since firefox opens MANY instances even with only ONE active window, this very quickly uses all available memory (4gb) causing a full laptop crash.

More concerning is that CLOSING the worst instance of memory usage STILL leaves the single open page/tab open, so what exactly was the memory eating instance actually doing ???

I have included a screengrab of the many remaining instances of firefox in windows task manager AFTER closing the main culprit.

I have also included a screengrab of all the adblockers I use which I believed would limit unnecessary memory usage, but does not seem to be effective.

Many Thanks

Hi!

I've noticed dropped frames in videos for a while now, but only recently tested the issue. Using youtubes stats for nerds, I found that when videos have a small viewport resolution, it starts to drop frames. (I would test with other sites but only know of youtubes stats for nerds system to detect issues like this) For example a viewport resolution of 1250x703 does not drop frames, however by unmaximising the screen and the viewport resolution drops to 681x383, it begins dropping frames.

Using my 2nd monitor which has a smaller actual resolution, the video drops frames unless fullscreened, see recordings below. Test A | Firefox Maximised but video not fullscreen Test B | Firefox Maximised and video fullscreen This issue also occurs with picture-in-picture mode.

Disabling hardware acceleration fixes this issue but for some reason only affects firefox, using MS Edge with "graphics acceleration" enabled does not result in this issue. Is this potentially an issue specifically with how firefox handles hardware acceleration? Also since I require hardware acceleration to be enabled for 3D model work in my browser, is there something I'm missing here that would allow me to keep hardware acceleration on but not have this issue?

Any help is much appreciated, thanks!

I'm using the vertical tabs feature. I also tried enabling the "Expand sidebar on hover" option, which minimizes the side bar, and only expands it when you hover on it.

Issue: I have a lot of open tabs, and I'm usually working with the ones at the bottom of the list. When the bar minimizes the scroll position resets back to the beginning. So, every time I want to select a tab, I have to scroll back down, which makes this feature very hard to use.

Expected behavior: After the vertical bar minimizes, and I hover again, it should keep the scroll position.

I have a new macbook air running Sequoia 15.3.2, firefox is up to date, my battery which should technically last about 12 hours and I only get 5. Ran through everything with Apple and they said it is a Firefox issues. I don't have any extensions, add on etc. Thoughts?

I am sorry if this is not the place to ask this question. I am new to web development and have been trying to solve this issue for days. I have an ESP32 acting as an http server. I have developed web pages which have separate html, css, and javascript files. These work as expected when delivered locally (i.e. I double click on the the files), however, when they are served by the ESP the style sheet is ignored and I get the message

The stylesheet (url) was not loaded because its MIME type, “text/html”, is not “text/css”.

from Firefox debugger. The stylesheet is ignore across all browsers (Firefox, Chrome, Opera, Edge), however the error is only shown in Firefox. Normally, of course, I would expect an issue on the ESP32 side, however, the non-Firefox browsers do load the stylesheet (even tough they ignore it) and I am able to verify that the stylesheet is identical to the one served locally.

Oddly, if I open a Firefox tab and load the page, switching to developer mode causes several requests for the stylesheet and the styles are then applied. Subsequent refreshes of the page causes the style to be lost and closing/opening developer mode has no effect.

Although I have disabled javascript to try fix this problem, when javascript is loaded I get a similar message (except the javascript is loaded).

I believe I specified the MIME type because I exactly coped several examples

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8"/> 
    <meta name="viewport" content="width=device-width, initial-scale=1"/>
    <link rel="stylesheet" type="text/css" href="styles.css" />
<!--<link rel="stylesheet" type="text/css" href="name-of-stylesheet.css" />    -->
<!--    <script type="text/javascript" src="ESP-UI.js"></script> -->
    <title>My ESP32</title>
</head>

Thanks for the help!

Recently starting having the issue where some whites and the tab icons appear washed out and even glitched out and pink when using my PC. I haven't made any significant changes to my system as far as I recall.

Colours in other browsers and applications are effected. Going to the same webpage on both Brave and Edge shows the whites correctly. On all the games on my PC there are no glitches in colours.

I have tried a few fixes already: -Removing and re-downloading GPU drivers - Fixes the issue temporarily. After about 1 day the issue comes back. -Re-seating the GPU - No fix. -Turning off colour override in Firefox - No fix. -Uninstalling and reinstalling Firefox - No fix.

If anyone has an idea or knows the setting that may be causing this problem I would really appreciate it.

On websites, thumbnails will not display but appear instead as white boxes with small blue question marks. I am using a two year old ipad and my internet speed is 180.

This is a new bug, as of today.

If I click on each thumbnail the image displays just fine, but that is not ideal.

On a reddit forum, someone suggested typing about:config into the search bar but nothing happens when I do that.

Any ideas?

Firefox on MacOS in full screen mode makes the black offset between the screen edge and the Firefox window after logging in after MacOS is locked. It fixes itself when you exit the full screen and enter it again.

How to reproduce?

• Open Firefox and enter the full screen mode
• Close your MacBook and wait until it prompts you for your password or touch id
• The Firefox window has black offset between screen edge and the Firefox window, that was not present before
• Exit the full screen and get into it again, and the offset is gone

I am one of those old-fashioned guys who has a title bar on the main window, and inside this (from top to bottom) a menu bar (File/Edit/View etc), then the current set of tabs, then the address bar.

I can click in the address bar and the caret appears, but the moment I start to type anything to edit the URL the address bar jumps up to to the top of the window, covering up the menus and tabs, with a menu of suggested URLs that at times covers most of the rest of the screen. Some images attached to show what I mean.

This started in a recent-ish release -- it didn't use to do this.

How can I prevent this behaviour, so I can just edit a URL in place the way I used to without the address bar jumping to the top of the window?

Currently using FF 135.0 (64-bit), Windows 11.

Hello!

After the latest Firefox Desktop updates (not sure which one exactly, since I didn't notice the issue immediately), I've started experiencing a problem with copy-pasting text — specifically with line break formatting on Windows 10.

Instead of copying line breaks using the Windows-style carriage return + line feed (\r\n), Firefox now copies only line feeds (\n). As a result, the text appears as a single long line when pasted into native Windows applications — which breaks the expected formatting. This behavior mainly affects:

• Text editable fields (e.g., contenteditable or textarea) in modern web applications.
• Code blocks or snippets (such as in Markdown or monospace) copied using "Copy" buttons (e.g., in ChatGPT or GitHub).

At first, I noticed this only when copying code from ChatGPT using the code-snippet copy button. But now it happens in almost all editable text areas — if I enter text with line breaks manually, and then copy it, those breaks do not appear properly in native Windows apps. For example:

• In Google Sheets, I often edit text with line breaks in a cell, but when I copy it back, it's all flattened into one line.

Right now, I have to fix this using scripts that replace \n with \r\n, but that's a very inconvenient workaround.

❗My main question is: What changed in Firefox that caused this behavior? This used to be reliable and feels like a regression. It’s a very basic feature and critically important for my daily workflow!

🔧 Follow-up questions:

1. Can this be fixed in a future Firefox update? Will it be addressed?
2. Is there a way to fix or configure this behavior right now via browser(settings, configs)?
3. Is there an extension or workaround that can restore the \r\n format without manual scripting?

Affected apps:

• ChatGPT
• Google Spreadsheets
• Trello
• ProtonMail (regular text copying)
• (more)

Thanks in advance for any clarification or suggestions!

Hello,

I checked the troubleshoot and gave all the necesarry permissions on my Mac for Google Meet to use my screen (allowed audio, video and screen recording). Nevertheless, I cannot manage to share my screen on Google Meet. As shown in the screenshot, it offers the option to share my whole screen (I cannot select a window or a tab...) but for my audience neither this is working.

Could you please help me fix this?

Many thanks in advance!

When I scroll some sites with the touchpad, it doesn’t scroll smooth like on windows. It scroll brutally 3 lines after 3 lines. I can’t scroll a half line for example. Even if I activate “smooth scrolling”, it doesn’t scroll with the precision and the speed of the hand. I don’t if It’s a mistake in the code of gecko or in the code of firefox but could somebody fix it?

Win11 Firefox 138.04 It appears some of the shortcuts on the Newtab page are preloading somehow.

Where are these coming from? Sidebar is off. I have all preloading off, all suggestions of every sort off, any predictive anything off.

I am not experiencing this on my win10 machine.

How do I stop this?

Try to get "tvlistingszap2it.com" --(which I have been using for 5 years)--- but it opens "newsnation" Started doing this on 17 Mar, 25. What is wrong ?? Can you fix it ??

As detected by Malwarebytes, it keeps blocking the site, quarantining the site, and the site in question is, mysearchengine.co. I do not know why this site keeps popping up, it's irritating. As such, I want a way to completely remove this weird search engine.

I'm on Firefox mobile, and I keep having this issue, and trust me, I've searched for solutions, but they just haven't worked out. Wverytime I open the Firefox app, it asks me to "get started". I've had Firefox for nearly a year now and it's my default browser. The only thing I can think that could be causing this issue would be me recently syncing my account onto my computer, but that was a little while ago and it used to not do this every time. Now it is. Please help?

Even though CPU and GPU utilization is very low during 8K60fps Youtube playback in the Firefox browser on my base M4 Mac mini, the struggles heavily to play this, drops tons of frames, and the video almost stops playing.

8K 30 fps is not problem, and since utilization is pretty low, that doesn't explain the poor performance.

So please optimize 8K60fps Youtube playback on all platforms in the safari browser, but especially on Apple SIlicon Macs.

I have a requirement where instead of showing the 404 error or 503 error on screen, I want to display a blank screen. I have already tried to set the following configs to false -

security.insecure_connection_text.enabled security.insecure_connection_icon.enabled security.insecure_connection_text.pbmode.enabled browser.ssl_override_behavior security.ssl.errorReporting.automatic security.enterprise_roots.enabled security.tls.version.min

Is there anymore steps to do or any userChrome.css script is required.

PS : I cannot use any extension or addon to do that

When using chat software, there may be shortcut key conflicts, and the sidebar will still open when using shortcut keys even after being closed.

In the settings, the AI robot is turned off, but when using shortcut keys, the options for the AI robot will still be turned on by itself and cannot be turned off.