Firefox Community Forum

在 Firefox 内部：

通过 JS 触发的新页面 通过 a.click 触发的新页面 甚至 rel=noopener 都会被标记为：

“related browsing context”

进而共享同一个进程，新页签因为内存占用过高，导致旧页签卡死。

通过设置

1. 添加 COOP 响应头 add_header Cross-Origin-Opener-Policy "same-origin" always;也无法解决

设置空白页再重定向也无法解决

I love Firefox and NEVER use Safari. I thought something had happened to my MacBook Air, stuck space bar or maybe even a virus? BUT the space bar issue doesn't occur when I use Safari. The issue is this: I will use Firefox (for everything). All of a sudden, the space bar becomes "engaged" and my text starts scooting across with spaces between it. I can hear it "stutter" a sharp sound each time it lurches along. I can then open up a word doc and the thing follows me there. Or when trying to close an unsaved word doc to prep for closing the computer. I restart the computer and to begin with, the spacebar issue is resolved but before long (sooner and sooner) it begins again to the point that I am restarting my computer now within about five minutes. I have uninstalled and re-installed Firefox to no avail. BUT, I can use other programs without problem as long as the problem hasn't already begun again, via Firefox. What on earth? I am now stuck using Safari... I have the most recent Firefox installed. I just re-installed the program a second time, yesterday. I don't want to open the program or I'll end up turning it off and on again and lose all of this but it was updated as of yesterday but I keep up on all the updates, all the time. It's been going on...about 4 weeks? But it started with occurring maybe once a week, then once a couple days now to the place it is multiple times to constant, during a day. I cannot use Firefox until this is resolved. Thank you for whatever help you can offer. I've run the diagnostic /first aid stuff to no avail through my utilities.

Hi, for about the last week (23 Feb 2026) when watching videos in my Firefox Browser, there are short stutters. First noticed in Youtube, so looked for updates to UBO and other extensions. Then noticed the same thing in BBC iPlayer and my4 streaming. It also happens when watching my media via Plex in the browser. It is not my network bandwidth or speed.

When I watch media via my Plex app or videos on VLC media player, there is no stutter.

I have included a link to logs recorded in Firefox profiler as suggested by someone on Reddit. firefox_profiler_2March26 https://share.firefox.dev/4b4moC0

I don't know if this is caused by a Firefox update, a Windows update. Laptop: Asus ROG Flow X16 (2023); Intel i9-13900H, Intel Irix Xe; NVIDIA RTX 4070 (mobile) Firefox 148.0 (64bit)

All drivers up-to-date. Please let me know if the link does not work - my first time trying to upload a link from profiler.

Thanks all.

I've noticed in the last few days that I'm periodically losing keyboard character input on sites following the update to the latest version - 148.0 (64-bit) I thought it might be a power issue with my WiFi keyboard and swapped out the batteries but the issue has persisted and I haven't experienced it when testing in Edge and nor have I seen it when using Excel or Notepad++ which I use regularly. Keyboard input actually froze for 4-5 seconds in inputting the last sentence. The problem is presenting on a number of sites - e.g. Reddit and YouTube. I do use the Ublock Origin extension but have been doing so for quite some time. I did report an issue with the mid screen search bar a few days ago and believe that is to be corrected in the update of 10th March. Is this also a known issue with the update?

warum ist die obere zeile mit dem kreuz beim start nicht mehr da? Sieh die markierung im Bild! immer wenn ich firefox starte mus ich es erst nochmal minimieren und dann wieder öffnen. was soll der scheiss

und Könntet ihr eure hilfe auch mal auf deutsch machen dann könnte mann wenigstens was lesen ode alles extra übersetzen zu müssen

For those of us that do want to use AI for work performance enhancement purposes, I have a question and also a comment for the Development Team. Here is the scenario real quick. I use Mozilla Firefox as my trusted browser today and that means that I open other AI systems such as ChatGPT, Grok, Gemini, etc. within this browser and could at times be running multiple browser sessions at the same time. My question is, will the Mozilla new AI Features attempt to try and compete with my other chat sessions for data capture, response and participation if I keep portions or the whole system enabled? The last thing I need is Mozilla AI as the selected browser now interfering with my other work flow processes in anyway including just listening along which would significantly increase the amount of resources used to run the Mozilla AI in parallel with other AI systems on my computer. I have heavy work loads at times and am already experiencing browser delays in processing data (even when setting up separate project chats for specific tasks) because of too many added features within all of the AI systems like historical chat session quick links on the right side of the screen. That's a ton of data that ends up getting stored/cached, referenced and processed with each command executed. I don't mind using Mozilla AI within the browser for general personal surfing and Q&A purposes but I can see this potentially becoming a big issue for us creators working with large image data processing tasks in other AI systems via the Mozilla browser. I will unfortunately be turning all of these Mozilla AI features off to start because I am not sure there really is a clear separation path for resource allocations within the browser now keeping my experience fast and efficient. Most likely this will force me into using a different browser product for personal vs business until things are much clearer. Hoping to learn a little bit here and see that things like this are being taken into consideration, even if it is a product roadmap enhancement for release sometime in the near future. Thanks so much!

Hi,

I’ve recently noticed that after a Firefox update, the browser has become very slow and unresponsive whenever I open multiple tabs, around 5–10. Before this update, I could open many tabs without any noticeable lag.

Now, new tabs take a long time to load, scrolling within open tabs feels choppy, and sometimes Firefox freezes for a few seconds before responding again.

I’ve already tried restarting Firefox, disabling extensions one by one, and clearing the cache, but none of these steps have improved the performance. I’m using Windows 10 and the latest version of Firefox.

Could anyone suggest what settings or troubleshooting steps I can try to fix this slowdown?

Since I installed Firefox, every software program, webpage, document, email and new tab freezes for up to five minutes. I can't get anything done. Please help! I tried the suggested steps but nothing works. I am not happy with Firefox at all.

When I wake up Firefox from sleep overnight, it is unresponsive until I force quit. I am on v147.0.4 on my M4 Mac Mini. It doesn't happen in shorter sleep periods. I can click something in it and then when I switch to another app, it responds. But the browser on normal interactions won't respond at all.

2026Feb24

Dear Mozilla,

I use Firefox as my primary web browser.

I am constantly having to Force Quit Firefox in order to free up storage.

Please work on making Firefox handle storage better.

I always have multiple tabs open in my browser. Previously, I could easily open (and switch between) 20+ tabs (I have 16GB of RAM). Recently, after opening five tabs, the Task Manager shows 10-11GB of RAM (88-90%) in use! How can this be? I cleared the cache and history, but it didn't help. I installed several RAM cleaners, but none freed up the required amount. None of the five programs worked. Where does that 15GB of RAM go when I open Firefox? When will you finally implement something like Google Chrome—they free up RAM for active pages when inactive ones are opened. Maybe it's because I have so many inactive tabs that the RAM is disappearing? But I had just as many tabs before, some of them inactive, and fewer than 20 active ones, so I could easily open another 20. And now I can't even open five new ones. What's happening to the browser?! SOS!

Firefox 147.0.4 (aarch64) "hangs" for 30 seconds to 1 minute when I launch it on my MacBookPro (OS Tahoe.26.3). Itwon't open the simple web page I have Firefox set to open when it launches -- and I can't navigate to any other web pages. When I try to interrupt, I get an Apple spinning beach ball until finally, Firefox opens that first page.

After working with Apple tech support, I have disabled a number of content barrier Extensions in Firefox-- which Apple tech support felt might have been causing this behavior. Nothing works. And I hesitate to run Firefox without some of them.

I tried deleting my Firefox user profile from my computer, but all that did was prevent Firefox from opening at all.

How can I stop this?

[edited email from community support forum]

I’ve encountered a problem with Firefox that it fills up the RAM memory to the brim (12Gb) and especially when you’re on Facebook, it doesn’t empty the RAM memory but the data remains, you have to close Firefox and lose your web page, it just fills up, Why, should it be like this, very annoying!!!? :flushed_face: //A-B/Sweden

YouTube playback freezes for a second or two every few minutes.

I have a recording with the Profiler that includes the stutter. It shows a memory drop and some "jank - event processing delay" just before the stutter happens 1m52s in: https://share.firefox.dev/4rzMNyD

My system: Firefox 147.0.3 (64-bit) Win 11 Home, version 25H2, OS build 26200.7840 Processor: 12th Gen Intel Core i5-12450H Graphics: NVIDIA geForce RTX 4060 Laptop GPU

'I am running fiefox version 147.0.3 in MacOS version 26.2. Every second time I start the program firefox tries to take 15GB of memory. The process does not respond (as this is equivalent to more than the memory available plus the swap space). I have to kill the process and the second time the program has standar memory needs. How can I help developers?

Greetings. Am running Firefox 147.0.4 (aarch64) on a MacBookPro running Mac OS Tahoe 26.3. When I first launch Firefox, it sits and does nothing for 30 to 45 seconds, I have it set to open a National Weather Service forecast page at startup, but even if I try to type in a different URL, Firefox won't allow me to do anything --or even quit the application -- until that first web page finally loads. Have tried clearing all history, including cookies and site data, but that does not help. The hangup was even longer until I worked with Apple tech support to turn off some universal add-ins like Content Barrier (Intego) or anything that acted like a VPN. Apple told me the hang is apparently caused by a Firefox add-in or extension. But I can't figure out how to find any or how to turn it off.