Firefox: форум сообщества

I have a problem with 'efficiency mode' in Windows 11. Windows 11 forcefully puts many of Firefox's tasks into efficiency mode marked by green leaves within task manager in processes tab. It doesn't seem to do this to anything else except Steam Client WebHelper. My Laptop is always in max performance mode in all possible settings as it is always plugged in (this does not influence efficiency mode). It slows down performance making things take longer to load and might even break them. If you try to enable efficiency mode on a task it even warns you of this: 'Efficiency mode will lower process priority and improve power efficiency but may cause instability for certain processes. Do you want to continue?' There is no way to permanently disable it. Currently out of 19 tasks 8 are in efficiency after I woke up my laptop from sleep (I have 5 tabs open). Only way to stop it is to manually disable each one by one (right click on each task and disable efficiency mode). But Windows 11 will turn them back on automatically usually within a few seconds (it seems to depend on opening new tabs, reloading them or waking up the PC from sleep mode). From looking it up online there seems to be a way to disable it in browser on Edge and Chrome but that might be something else (I do not use the so I'm not sure). There was a solution for Chrome but it doesn't work on Firefox.

Is there any way this can be disabled permanently through Firefox or Windows 11?

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!

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!

Dear Support Person,

Yesterday, after being notified that an upgrade was available, I executed the upgrade to version 152.0.

The upgrade completed successfully with my eight tabs populating on the left side along with a new tab showing all the features of the new upgrade.

I opened my Gmail tab and my Yahoo mail tab. Eventually, Firefox froze up, saying it was Not Responding. I looked at Task Manager and saw that Firefox was continuing to grab up memory. I ended the Firefox process in Task Manager.

I then opened it again and deleted all the tabs except for one. It continued to grab up memory.

I then opened it in Troubleshooting mode. It errored out, and I sent the report to Firefox support.

The only thing that has changed is the fact that I ran the upgrade to Firefox. Nothing else has changed.

Firefox has been my go-to browser for years. I am using Chrome as my access to the internet now, and cringe every time I go into it.

I hope and pray that you can bring my Firefox friend back to me.

I am anxiously looking forward to hearing from you.

Take care and God bless!

~ Kyle P.S. I just tried getting information from about:support. I was able to copy the raw data and then the application crashed. I sent the Crash Report to you folks. The raw data I pasted in the Troubleshooting Information box.

Gentlemen, isn't your browser using a lot of RAM? I've been freaking out about it in recent years. That's only with 25 tabs open!! Despite the fact that the system was installed just a day ago, without any tweaks!!!

I have been using Firefox forever. It has been running very slow and bugging out especially with you tube on close. I've been working on this for a couple of weeks and am about to give up. My self built system is about 10 months old. Am using a completely debloated MS 11 pro 25h2. Did not ask for AI from Firefox and have disabled AI in Firefox and copilot is long gone. I have tried everything. Am about to quit firefox. Have refreshed firefox and prevented firefox from running in MS win 11 pro "efficiency mode". I usually have to exit firefox with task manager - there are usually 17 instances of firefox running. Mozilla has become Microsoft.

The system: Gigabyte B650 mobo, 32 gig of DDR5 6000, AMD 7700X processor and an Asrock 9060 graphics card with 16 gig DDR6 Vram. All other apps are running just fine. So I don't think a lack of compute is the problem.

Help please! Thanks in advance!

Been using Firefox for over a decade. But lately is has become so slow now. Often freezes up if more than two tabs are open or a website is in any way very complex. What settings and issues should I check? What has changed? I can run the same sites on Brave and Edge browsers with no issues or not nearly as slow and bogged down.

Background: I have Firefox on a brand new Thinkpad X1 Gen 11, running Windows 11. I have used Firefox with multiple Google accounts on an older machine for 5+ years. That machine is running Windows 11 as well.

Problem: I cannot add multiple Google accounts in order to access Gmail, Drive, etc. I have added the first, my personal account. When I select "Add another account" from the menu icon in Gmail website, it takes me to the add account page. As soon as I try to highlight the name of my personal account, it freezes and the only option is to shut it down. To be clear, this is trying to add a Google account when browsing, *not* trying to create multiple profiles in Firefox. I have refreshed, reinstalled, and searched for a solution. What is going on?

Description: We have encountered a significant performance issue with NativeMessaging API in Firefox when an extension communicates with a native application.

In scenarios where many objects must be enumerated (e.g., ~458 certificates), Firefox is dozens of times slower than Chromium-based browsers.

Environment:

Firefox (latest stable, reproduced in 2025)

Windows 11 x64

Same machine and same native plugin tested in Chrome, Edge, Yandex Browser

Steps to Reproduce:

Create a WebExtension that communicates with a native application via NativeMessaging.

Perform enumeration of a large number of objects (≈ 450–500).

Measure execution time in Firefox vs Chromium.

Actual results:

Firefox: enumeration of 458 objects takes ~2 min 30 sec

Chromium/Edge/Yandex Browser: enumeration of the same 458 objects takes ~5 sec

Additional tests: Round-trip time (RTT) for a single message:

Firefox: ~73.7 ms

Chromium: ~0.3 ms

Because the extension and the plugin exchange a large number of messages, this performance gap becomes critical.

Expected results: NativeMessaging API in Firefox should perform at a level comparable to Chromium browsers, so that extensions relying on heavy message exchange remain usable.

References: Bug 1288912 – Native messaging performance is extremely poor

Although this bug is marked as resolved, performance testing still shows a major discrepancy in the current versions of Firefox.

Question: Is there any ongoing work or plan to optimize the implementation of NativeMessaging API in Firefox to address this performance issue?

Since a month or so, Firefox browser freezes when playing youtube videos. Simply closing the app and restarting won't do the trick, I am forced to open the WIN Task Manager and manually "end task" before I can watch youtube videos again ... until an hour later, or lucky a day later, the same drama unfolds. I run the newest version of each, Firefox and Windows 11. No new extensions or plugins have been added recently. What is to do here? I'm since Netscape on this route and would hate to switch to another browser... :-) Thanks in advance!

I have around 60 tabs open accross 5 windows, and whenever I try to open a new tab, Firefox takes many minutes to load completely. I've restarted Firefox and the problem is solved for a few days, and then it persists. I've been using Google, but I want to keep using Firefox. Fix it now please.

This problem, annoynace, has become overwhelming of late. It appears everytime a have a FF version download, this problem increases. Any help advice would be appreciated. Dan

Sorry for my language.

The latest versions of Firefox 141 (and 142 beta 1) do not allow the Windows taskbar to appear when I move the mouse to the bottom of the screen. This happens on Windows 10 with the auto-hide taskbar setting enabled. In previous Firefox versions, this worked fine (except for one older version where it briefly broke). I’m not running Firefox in fullscreen mode, and I have no modifications or themes that could interfere. I tested this on a fresh, clean installation of Firefox — the issue still occurs. After downgrading to versions 140 and 139, everything works correctly again. Interestingly, I also tested the Firefox 141 Release Candidate Build 1 from here: 🔗 https://ftp.mozilla.org/pub/firefox/candidates/141.0-candidates/ In that version, the issue only occurred in private browsing mode. Could someone please help me resolve this or confirm it as a bug? Thanks in advance!

'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?

Ever since I got 133.03 my Dell cpu freezes a lot. Over the last hour it froze 15 times. This is terrible reliability.

I hired Dell Tech Support and they checked my software and there were no issues. I have run advance Norton features and there are no problems. Therefore the issue is NOT with my 20 month Dell computer.

Firefox has always been reliable until late August. For four weeks it would freeze and lock up. by the end of Sept it was slightly better and then fine in November. Now it only freezes, put the mouse over the image and it freezes. Play with it for a while and it unlocks.

I am totally fed up with Firefox. I'll be starting my taxes soon and year end things and can't afford to have all these issues and rebooting to help eliminate the issue.

When is Firefox tech support going to help me? When is Firefox going to fix the issue? After Christmas I am looking into the Microsoft software......enough is enought!

Hello, I have noticed that using firefox without closing the browser for a while causes the memory to keep rising. It looks like it has a memory leak. After 3 days of watching YouTube I was using 4GB of memory. It was causing Slow Downs.

I have included 2 images with what is actually running and I have 2 Tabs in Standard Browser of Google and this Tab for this report then a YouTube dedicated browser using split tab.