Firefox Community Forum

I've been using Fire Fox for decades, but lately it is so slow, I thought there was something wrong with my Windows 7 ultimate. I've done full Windows reboot, to no avail. Then I see the internet t hat FireFox is starting to implement AI. I thought that may be the issue, but after looking into it, looks like that isn't an option with my old Win 7 OS. So if that isn't the problem, how can I find out what is bogging Fire Fox down? I keep a watch on my CPU usage, and the usage is going nearly to 100%, when it used to barely go over 10%. When I check the actual CPU usage, it shows as many as 15 or more items tied to Fire Fox.

Is this all a result of continued use of Win 7? I'm planning to move to Linux, but that will take me some serious time and effort. Gerald

I've disabled extensions, changed settings, and reinstalled multiple times, but Firefox won't quit stuttering constantly. Other browsers work fine on my computer, and Firefox doesn't seem to be using much memory.

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.

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?

Hi!

I've had issues with Firefox now for quite a while and they only seem to be getting worse. Performance is really bad, it's lagging while browsing, especially infuriating when typing as the letters come out at a stuttering pace. I've tried disabling extensions one by one, I've tried troubleshoot mode and experienced no major difference.

If I can't solve this soon enough I won't be able to keep using Firefox, as the experience is so frustrating. And it would be a shame since I've come to like it quite much.

Thanks!

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.

Whenever I wake my mac from sleep, Firefox is unresponsive. I believe the app is not dead, just not repainting the window. Sometimes if I 'hide' Firefox window behind some other app window, then bring it back to top, it'll re-paint.

For a while I fixed the issue by disabling GPU usage in firefox. But now, even that isn't helping. Then for a while, removing and reconnecting the USB-C connection to my external monitor would fix it, but now that doesn't help.

Have to quit firefox completely and relaunch. Then the app is working again.

Using Firefox 146.0.1 (64-bit) on Mac (2.4 GHz 8-Core Intel Core i9, AMD Radeon Pro 5500M 4 GB, Intel UHD Graphics 630 1536 MB, 16 GB 2667 MHz DDR4, macOS 15.7.3)

I've used Firefox for years, but recently Firefox is unusable on Mac OS 15.7.2 because it's hogging all the RAM over time. I get a spinning beachball on my MacBook Pro. I look at the RAM being used and it's even over what I have in the computer. I have and always keep Firefox updated to the latest version.

After update tahoe 26.1 update on mac firefox keeps stalling are they fixing this before i switch? I have a lot of tabs and things here but if you keep freezing I am going to switch. Are they fixing this? I already did all the things you suggest online. It freezes, and I can't keep this up?

i run Firefox on Win11. When i go to a website, and open several tabs, e.g., 10 or more, firefox just sits there and no longer works on that site. Basically Firefox is becoming quite worthless as a browser for me. The reason i use it are the extensions. This is something that has happened within the last 6 to 9months or so. What is going on. Is there now some limitation of how many tabs you can open? The site with this problem is: https://www.bellazon.com/main

Anyone got any ideas as to what is going on here?

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.

While running Firefox on MacBookAir with macOS 15.7.2 to browse simple websites I keep getting the below warning message. I may have 2 or 3 other apps open (like Apple Mail, MS-Word, Preview). "Heavy memory usage You're running out of memory and your Mac may become noticeably slower. Consider quitting some applications. Firefox 2,48 GB" So I quit Firefox to re-open again and continue my work. Does somebody has an hint where this message can come from ? Any settings to change on my MAC ? Thanks for helping

Firefox is still freezing when entering incorrect info in the Google Sign-in page (when I try to sign in on www.youtube.com); - if I enter the wronglogin info & press enter, the firefox window becomes useless & I cannot cancel/close the window. & Help menu is greyed-out for the frozen window & any new window I open;

- i have to go to macOS' Activity Monitor & Force Quit the 'AuthenticationServicesHelper' (Firefox), then the window becomes responsive. This makes it impossible to use Firefox & if someone didn't know this, they wouldn't know how to fix it.

- this has been an ongoing issue & the previous time i submitted this, it was removed for "not being a question" (???) but it still important & I still hope it gets fixed someday?

Hello, today I have set up a new account for work and I have trouble signing in. Actually, I manage to sign in, however I am then shown the screen which gives me the option to create account recovery key and the browser freezes completely. I am unable to click on anything, the only option is to go to the Task Manager and kill the program there. Then, when I open Firefox again, I am not signed in (even thought I recieve the email about a new sign-in to mozilla) and have to try the process again, only to experience the freezing browser again. How can I solve this or troubleshoot? I have Win11, my broser is supposedly up-to-date. Thank you! Anna

What are your best tips for optimizing Firefox Desktop for daily use, especially in terms of speed, memory management, and handling multiple tabs without affecting overall system performance?

What causes Firefox to freeze when two video windows are opened, i.e. in a new tab, the video windows immediately start to freeze? I use Windows 11. Other browsers work fine, only Firefox freezes with two windows open.