Firefox Community Forum

Whenever I open a new firefox page externally, such as from the system tray or by opening a link from outside firefox, nothing happens for about five seconds and then it loads normally. When I open a new firefox page internally, such as from file ---> new window or by clicking a link within firefox, it loads instantly like normal. This has been happening since yesterday (3/13/26) evening.

I have already tried all of the following fixes and none have done anything:

Clearing firefox startup cache running firefox in troubleshoot mode running an older version of firefox disabling all my extensions disabling my antivirus disabling hardware acceleration disabling captive portal detection making sure both firefox and windows 11 are fully updated refreshing firefox reinstalling firefox rebooting my PC disabling IPv6 preventing accessibility devices from accessing my browser clearing my cookies

I rarely turn my laptop off, when I'm not using it I put it into sleep mode. Firefox absolutely hates this though, and after a few days it will slow to a torturous crawl. Everything becomes horribly irresponsive, feels like nails on a chalkboard. It can even get to the point where it will randomly delay my cursor in Windows 10 itself by 10 SECONDS along with some bleed into other programs while switching between them. Fully closing Firefox then re-opening it will reset the issue, starting the timer again, but I hate doing this because I have doing that set to log me out of various sites which I then have to re login to, letting the torture boil until I give in. This has been my Firefox experience on laptop for at least 5 years now. Other forks of Firefox have this same issue.

I am leaving Firefox in the torture state currently to troubleshoot here. Currently the memory usage on Firefox is 6GB at 54% of my total ram, which is being used at 84% total. Total CPU usage is 23%. Wrote this on my desktop for my sanity so that's why there's no troubleshooting information.

I use Brave, Firefox, Firefox Developer Edition and Thunderbird. Brave: 600mb Firefox Dev: 600mb Thunderbird: 200mb Firefox: 800mb Why is Firefox using too much memory? Especially as I am running Firefox Dev as a direct comparison. I don't have any plugins on Firefox. Firefox Dev has uBlock Origin alone. Brave has a few plugins.

Recently I've had this issue (on reddit) where after I expand a video in the feed, and start scrolling, all the visuals freeze.

I know it's only the visuals, because I can still interact with the website (usually unexpand the video, or pause it) with the image still frozen and audio still playing.

I can fix it by tabbing firefox down, and then up again. While researching I found the profiler, and finally managed to capture the moment it happened.

I'm no stranger to technical stuff but it's a loooot of data to process, I did a "clean" profile recording as well where I did the same action and where it didn't freeze, and I can't really make heads or tails out of what the issue is.

The recording managed to capture the phenomenon and I only clicked twice during that period, to expand two reddit expando videos, the second one is what caused the issue when scrolling. The only thing I see is a spike in memory usage

Not sure if I can (or should) upload the profile recording here or what, but it's been bugging me a lot.

It's pretty tricky to replicate because it seems to be random when and what triggers it, even expanding the same videos doesn't replicate it. Sometimes I go days without it happening, sometimes it happens 6 times in a single session.

I've added some screenshots of various views of the profiler/stack data.

I have an Nvidia RTX 5070ti GPU, hardware acceleration is on, AMD Ryzen 7 9800X3D processor.

I think I might have enabled some rendering settings in about:config, maybe it's related to that but I don't remember exactly what.

Maybe it's due to some windows "game optimisation" or the GPU and CPU-GPU fighting?

I have no problems watching videos while playing games or anything though.

Hi Everyone,

I’m Harmandeep Singh Kandhari from India, A Health and Wellness Motivator and Now, Recently, my Mozilla Firefox browser has started using much more memory than usual, and multiple tabs cause noticeable slowdowns. I haven’t installed many new extensions. What steps can I take to identify the cause and optimize Firefox performance without resetting my entire browser profile? 🦊💻

Thanks, Harmandeep Singh Kandhari

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.