Firefox Community Forum

For the past 15-16 days, Firefox has been consuming extremely high memory.

The problem: - When Firefox first opens, it starts normally at around 300-400 MB - But after using it for about 1 hour, a single Firefox window grows to 1-2 GB of RAM - This keeps increasing the longer I use it (memory leak behavior) - Currently Firefox (41 processes) is using over 5,131 MB total memory on my system it's normal but after 1 hour a single firefox window grows to 1-2 GB of RAM

What I have tried: - The issue happens consistently every day for the past 15-16 days - Other browsers like Chrome and Chromium use much less memory in comparison

System info: - OS: Windows 11 - Firefox version: latest version 148.0.0.0

Please help me fix this memory leak issue. It is making my system very slow.

Initually I was having issues where I couldn't get the print menu to load up (forever stuck trying to load the preview), however since then it has progressed to downloads refusing to download and the hamburger menu in the menu bar doesn't react when left clicked at all.

In Firefox's Task Manager, how do I know which tab is using which subframe(s) process?

For example, let's say I open Firefox and with only one single tab open, I open the following web page: https://audioplugin.deals/product/best-of-zampler-collection/

That page apparently includes content from several third-party websites because when I open it, Firefox's Task Manger shows processes for the following:

https://audioplugin.deals https://cloudflare.com https://google.com https://hcaptcha.com https://soundcloud.com https://stripe.com https://stripe.network https://stripecdn.com

The process for "https://audioplugin.deals" is the only process with a tab. All of the other processes are subframe(s) only, with no mention of which tab is using them.

With only one tab open, I intuitively know that all of these processes must be used by that one tab. But like most people, I browse using multiple tabs, and once you open multiple tabs, it becomes (as far as I can tell) impossible to determine which subframe(s) process is used by which tab. This makes it impossible to determine which tab is behaving improperly or erratically when there are issues (for example, when one of those subframe(s) processes is consuming an unreasonably large amount of memory or CPU cycles).

I am just an average end user and want to alert you to my problems and would love a solution. I am sorry that I don't have the kind of specificity in the details which might help (I am too busy doing other things and when firefox becomes too much of a pain, I generally close it and switch to another browser). I am providing my general observations. On my updated windows 10 64 bit system, firefox v148 seems to have made the browser unusable for me. Other browsers do not suffer similarly (Chrome, Edge, Opera, duckduckgo). I have had these types of issues with Firefox in the past, but they resolved with prior updates. I am at the point of switching to another browser - I hate the thought of it, but Chrome seems to be the most stable and functional. Symptoms:

• Firefox browser and the computer gradually become slower as firefox starts hogging cpu and memory and starts using a lot of power
• extensions stop working - eg, Keeper extension stops filling fields or fills incorrectly, Malwarebytes extension seems less responsive, running background sounds makes things even worse (https://www.mynoise.net/) and web pages with continuous updates (eg, map.purpleair.com) stop working altogether
• other pages stop loading, load with errors ('bad connection') or load very slowly, especially, but not always, those with more security, eg, my bank or retirement funds sites.
• after i close Firefox and start fresh, symptoms resolve, then rinse and repeat.

The previous version worked great and seemed to solve similar issues I have had with earlier releases. I assume the last stable release for me was one of the 147 versions. but when things are going well (which is most of the time), I'm not watching closely, or at all.

Second time asking for help: Firefox "hangs" for 30-60 seconds the first time I open it on my MacBook Pro. Am running Firefox 148.0 (aarch64) on Mac OS Tahoe 26.3.1. This has been going on for three months. Have tried uninstalling Firefox and using AppZap to erase my Mozilla profile from the Mac -- rebooting the Mac -- and re-downloading a fresh copy of Firefox. I shut the Mac down for about an hour, rebooted, and Firefox launched right away. But the next time I launched Firefox on reboot, it "hung" again. Spinning beach ball for about 45 seconds before it then opened its default page at open. I do not run a VPN, and disabled some Safe Browsing "features" of Intego Virus Barrier.I tried to eliminate any other third-party extensions from my Firefox that might cause the delay. Am attaching an image of the extensions Firefox currently uses on the Mac. I absolutely <loathe> Safari, but can't have my Mac use Firefox as a default browser if it "hangs" on first launch. One last thing. Early on in the process, I tried deleting my Mozilla Firefox User Profile, but Firefox refused to start because it couldn't find a profile to launch with. So did not go there on this last attemt. Thanks in advance.

I'm elderly,so bear with me. Firefox very often slips off the screen or simply vanishes.Often it disappears to a thin,gray line at the bottom. Can't open a document and have Firefox available,too. I'm 84....are my fingers worn out? Dave P.

If I am on a website that is still loading in Firefox and want to change to another URL, then Firefox does not stop loading the old page. Once I click the "X", then it loads the new URL webpage. Shouldn't it stop getting data from the old URL the instant I load a new URL?