Firefox Community Forum

Watching any Bilibili live stream causes severe performance issues. The main problems I can observe are intermittent severe mouse cursor stuttering/frame drops or the cursor becoming unresponsive, accompanied by the taskbar process (explorer.exe) intermittently restarting.

I have tried disabling the Picture-in-Picture feature and tampermonkey add-on, modifying the Windows 11 registry to turn off MPO (Multiplane Overlay), adjusting browser hardware acceleration, and tweaking related settings in about:config, but none of these have been able to prevent the issue.

Select the text in the text input box to type (overlay typing), the Chinese input method will flash, then nothing will be typed and the selected text will disappear. 在文本输入框中选中文字进行打字（覆盖打字），中文输入法会闪一下，然后什么也打不出来并且选中的文字也不见了。 As in the following figure, it almost always happens when you select and overwrite text. 就像下面图中情景一样，对文字进行选择覆盖的时候几乎一定会发生。

For the past month this browser has been really slow. I have cleared cache, deleted all history and its really slow. I'm using starlink for internet. any suggestions

Hello there,

I’m experiencing high memory and CPU usage in Firefox, which is affecting my computer’s performance. One issue appears to be that “FirefoxCP Isolated Web Content” continues running even when tabs are inactive, contributing to increased resource usage.

Other browsers, such as Microsoft Edge, reduce memory and energy consumption by putting inactive tabs into sleep mode after a period of inactivity. I would prefer to continue using Firefox as my default browser, but I need a way to manage this level of resource usage.

Could you please advise whether Firefox offers a comparable setting, workaround, or planned improvement to reduce CPU and memory usage from inactive tabs?

Thanks for your help!

Dear Support,

Firefox exhibits significant performance and usability issues related to its cookie and data storage management. Despite implementing ad blocker extensions, the browser remains saturated with cookies and persistent advertisements. Regularly clearing browsing data and cookies is necessary; however, navigating to the settings menu is time-consuming. I recommend developing a browser widget that facilitates rapid data clearing directly from the toolbar or frame. Additionally, implementing a session-saving feature to preserve a set of pinned tabs upon closing and reopening the browser would enhance workflow efficiency, allowing for a quick start with a predefined workspace.

This is all happening while using it for simple tasks like search or copying a text.

Furthermore, the browser experiences severe performance degradation when utilizing certain web applications, such as Kapwing for video editing. Since uninstalling Vivaldi, I am considering migrating to an alternative browser due to these issues. Tasks that typically require one minute are now prolonged to hours, as the browser intermittently becomes unresponsive, effectively limiting usability. This sluggishness persists even after system restarts, with CPU utilization reaching approximately 50%, as detailed in the attached performance report. Notably, I encountered a significant delay—up to an hour—to correct a single spelling error or open a new tab, indicative of underlying performance bottlenecks.

Please address these issues to improve browser stability and usability.

Estimator Just tell me how long this is probably gonna take: 4 to 16 hours. Not kidding!

Version 148 is very slow. When there are 5-10 downloads, other websites won't open. That's why I use version 140. And why are there so many files in the folder - ....profile\storage\permanent\chrome

My Firefox browser was updated to the most recent version (153.0). And since then, it will always freeze up within a few minutes of me opening it, even in troubleshooting mode. Even if I keep clicking, it’s still stuck and I’m forced to close it.

I did turn off hardware acceleration before, and it still doesn’t work.

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

Hello, After the last update i keep seeing a blank page when i open a new tab or new page. i tried the troubleshooting mode but the same. i need to refresh every time i open a new page.

When my system slows down and takes forever to download, I go to task manager and find 15-20 entries for Firefox when I have only 1 or 2 pages open. Why are they continuing to pile up and slow down my machine and how do I stop it from happening?

Hello everyone,

I've recently noticed that Firefox has become slower than usual. Some websites take a long time to load, and occasionally the browser feels unresponsive even though my internet connection seems to be working fine. I've already tried restarting Firefox and clearing the cache, but the issue still occurs.

Has anyone experienced something similar or found a solution that improved Firefox's performance? Any suggestions would be appreciated.

Thank you!

Sporadically over the past year, a virus warning, purportedly from Apple, has locked my FireFox screen. I must Force Quit to unlock FoxFire. See images. Is this a scam?

When I launch Firefox, it uses well under 1GB in memory, but then it starts to increase that amount quickly in just a few minutes and gets up to 50+GB, causing error messages to pop up repeatedly until it uses all resources and locks up my computer. I have updated my MAC OS and the Firefox app, uninstalled the Firefox App and still have the same problem.

Please help

On a new laptop with Win11 Home (x86-64) with Firefox just installed, the cache size is 54 MB. When Privacy and Security -> Clear Browsing Data is clicked, Firefox hangs - no input is accepted and nothing appears to be happening. On closing Firefox and then reopening the cache size is reduced and Clear Browsing Data operates as expected.

Why is the cache size (54 MB) so large? Why does Clear Browsing Data hang Firefox?

fonts.googleapis.com is locking up websites for 40 to 60 seconds per keystroke. I have researched this problem and tried everything suggested, but nothing works. Much of the solutions include changing the settings used on menus which no longer exist. accounts.google.com is doing the same thing. This is driving me nuts. Help!!! Latest version of Firefox. Windows 11 desktop computer.