Firefox Community Forum

I've done recent updates (May 2026) and after having 3 updates in recent months, I still have difficulties with my video programs (both Zoom and "One-click) slowing down during my work which is 100% virtual. How can I revert to an earlier version where this was resolved, please!!??

Hi whenever I use my Google account to sign into websites (Google, ebay, YouTube, & anyother sites,) Firefox will become unresponsive, the window containing the tab i was using becomes unresponsive, sort of. - I can't click any open Firefox Tabs, - the red 'Close' radio button is greyed-out, so I can't close any tabs or the window - right-click is unresponsive, so i can't close tabs that way, but Command-W closes the tabs normally, but the others are still unresponsive.

- i can open a new Firefox window (with &/or without Tabs,) which works normally.

- & unrelated, but earlier, Firefox was running really slowly, Youtube videos were slowed down, but audio was normal, and scrolling was slow.

My Firefox 150.0.3 (64-bit) in Windows 11 on a Dell 9310 locks up when the XPS is put sleep and awakened after 5-minutes or so. No recent Extensions or Add-ons have been installed. I have yet to delete and reinstall Firefox, maybe that's the next stop. I just can't find the problem with my limited tools and experience. Thanks, and appreciate the help.

I was doing some work, when suddenly everything slowed, I checked my Activity Monitor, and it showed Firefox at nearly 20 Gigs of RAM & about 30% of CPU usage! I opened the Task Manager, and it only showed Firefox using 2 Gigs, and 25% of CPU. After a few minutes, the memory usage just as suddenly dropped down to the 2 Gigs as shown in Task Manager, and things seemed to be back to normal.

Why did this happen? I did nothing that would cause a spike, didn't open any new videos, or other high memory usage pages, or applications. I have seen FF showing a similar 20 Gigs of RAM usage, slowing everything down, several times recently, and wonder what could be causing these sudden spikes.

i tried firefox, zen and librewolf but every of them has the same problem. smooth scrolling is sometimes good but sometimes so slow and laggy, especially in a tab that has a video. in tabs that has a video always have that issue and tabs that not has a video does it sometimes. its like scrolling is in 60hz when it happens. i tried uninstalling lots of times but didnt fix.

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!!!

Hallo,

ich habe regelmäßig das Problem, dass Firefox quasi meinen gesamten Rechner ausser gefecht setzt indem nahezu die gesamte CPU Leistung und der Arbeitsspeicher in Beschlag genommen werden. Ich surfe in der Regel mit sehr vielen Tabs. Ab ca. 100-150 Tabs benötigt Firefox bei mir zwischenzeitlich 10 GB Arbeitsspeicher und mehr und benutzt die CPU zu 80-90% sodass der Rechner teilweise kurzzeitig nicht mehr reagiert und einfriert. Besonders, wenn ich 100 Tabs und mehr auf einmal als Lesezeichen speichere (Tabs auch nur schließen, da der CPU Lüfter schon dauerhaft auf 100% läuft), friert der Rechner danach erstmal für 3-4 Minuten ein. Ich verstehe nicht, was Firefox die ganze Zeit im Hintergrund anstellt, während z.B. 250 Tabs geöffnet sind. Tabs vorzuladen macht bei der Anzahl keinen Sinn und die Wahrscheinlichkeit, dass man richtig voraussehen könnte, welchen Tab ich als nächste wieder aufrufe und dieser dann schon vorgeladen ist, ist eher gering. Gibt es Möglichkeiten z.B.: - den zur Zeit verwendeten Arbeitsspeicher sofort zu leeren, ohne einen Tab zu verlieren oder dass Firefox geschlossen wird? - dass es dann längert dauert, wenn ich einen Tab anklicke, da dieser ja nicht mehr im Cache ist, und erst wieder in den Arbeitsspeicher geladen werden muss, ist selbstverständlich und vollkommen in Ordnung. - Kann man irgendwo einstellen, wie viele Tabs z.B. im Hintergrund aktiv sein dürfen? - Kann man den zu verwendeten Arbeitsspeicher begrenzen? - und was passiert, wenn die Grenze erreicht wird? - Kann man irgendwo an den Zeiten oder ähnlichem schrauben, wonach Tabs automatisch entladen werden? Chrome friert Tabs scheinbar automatisch ein, zu mindest ist die performance dort besser.

Es bringt ja nichts, wenn alles versuche wird im RAM vorzuhalten, damit es sofort da ist, wenn der ganze Rechner damit in die Knie gezwungen wird und am Ende das gesamte System nicht mehr zu bedienen ist. Vor einigen Jahren ist Firefox bei zu vielen Tabs oft abgestürzt, dann hat sich schon gebessert.

Es fehlt mir an Einstellungen zur Anpassung, was Firefox im Hintergrund vorhalt und was Tabs machen dürfen, wenn sie nicht aktiv bedient bzw. benutzt werden. Manuelles "entladen" kommt für mich nicht in Frage, da es zu aufwändig ist, bei extremen "Multitabbing".

Ich bin seit meiner Kindeheit begeisterter Mozilla Fan (seit Gründung von Mozilla) und verteidige und empfehle Firefox wo ich nur kann. Aber dieses Performanceproblem besteht schon sehr lange, ist zwar über die letzten Jahre besser geworden, dennoch zwingt es mich schon fast, nach einer Alternative zu suchen.

Generell fehlen viele Funktionen für Extrem-Multi-Tab-Benutzer wie z.B., dass man Tabs in der Leiste markieren oder sortieren kann. Ein großer Segen wäre eine Funktion, dass Tabs, die man bereits als Lesezeichen gespeichert hat oder doppelt geöffnete Tab, direkt zu erkennen sind, ohne dass man den Tab aufruft. Aber andere Thema. Ich benutze auch keine vertikale Tableiste, nur die horizontale klassische Leiste oben am Bildschirmrand.

Ich wäre sehr Dankbar über Tips zur Lösung des Problem mit dem Arbeitsspeicher.

Grüße

Over the past few weeks, my typing is continually being interrupted. It did this a few years back, but this is getting very annoying and I am soon to switch browsers if not fixed. BTW on any machine using Firefox, this is happening

I use multiple Firefox profiles and create separate desktop shortcuts for each profile using Firefox’s built-in profile shortcut option. I then pin each profile shortcut to the Windows taskbar so I can launch them independently.

The issue is that when I click one of the pinned profile icons, Firefox opens a new separate taskbar group/icon instead of attaching the window to the already pinned taskbar item for that specific profile.

For example:

• I pin Profile A and Profile B separately to the taskbar.
• When Profile A is already open and I click its pinned icon again, Windows creates another Firefox taskbar button/group instead of reusing the existing pinned Profile A button.
• Google Chrome profiles do not behave this way on Windows — each profile stays grouped with its own pinned taskbar icon as expected.

Is this a known limitation/bug with Firefox profiles on Windows taskbar integration, or is there a way to make Firefox profile shortcuts behave like Chrome profile shortcuts?

please help me make my computer run better,i have epb fiber optics and its slow and im sure my programs and everything is configured wrong

After installing Firefox 150, clicking on a window for a different application does not make that application active. Firefox is not letting me leave! I can switch by going to the sidebar and choosing a different application. None of the other applications exhibit this behavior. MacOS 26.3.1

Two questions; First is why does the Taskbar show "Firefox (2)" (see first image) Second: When trying to troubleshoot, I open Task Manager, and with just one tab open, I see Firefox (13); confirmed when the line is expanded. What is going on here and is it impacting Firefox performance; see 2d and 3d images? (Phone camera photos as PrintScreen is disabled for Task Manager which doesn't seem smart)

Today Firefox has suddenly started using ~20% of my CPU capacity, causing my cooling fan to run high most of the time. Since I had been running Firefox v.149.latest, I tried updating to v.150.0, but that made no difference.

It's not Firefox by itself (only Task Manager open) but whenever I open another tab with almost any website (including this one) that CPU usage spikes. What gives?!

Details: Running under Windows 10 Pro (yes, I have installed the ESU package, good until thi8s fall) on a Lenovo P1 Gen 2. Currently running Firefox inside a Sandboxie Pro v1.17.4 sandbox.

Please Help! -- jclarkw

I've just opened one simple Web site (in addition to Mozilla), and already CPU usage sits at about 20%! Please refer to my recent posts here at "Why is Firefox Suddenly Taking Over my CPU?" for the problem description. I'm re-posting simply in hopes that I can "send data" on this one from outside my sandbox. Regards -- jclarkw

Hello,

I’m experiencing a serious issue after updating Firefox to version 150. Since the update, Firefox frequently freezes and crashes, making it almost impossible to work normally.

My laptop has 16 GB of RAM, and I’m using Windows 10. When I check Task Manager, I can see that Firefox’s memory usage suddenly increases to around 7–8 GB, then drops back down to around 3–4 GB. The memory usage keeps fluctuating heavily.

Also, the number of Firefox processes/tabs in Task Manager keeps increasing, and eventually the browser becomes completely unresponsive.

Could you please investigate this issue and let me know how it can be fixed?

Thank you.

Anyway to fix the issue?

Name: Firefox Version: 150.0.1 Build ID: 20260427221700 Distribution ID: canonical-002 User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:150.0) Gecko/20100101 Firefox/150.0 OS: Linux 6.8.0-111-generic #111~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Apr 14 17:13:45 UTC OS Theme: Yaru / Yaru Multiprocess Windows: 1/1 Fission Windows: 1/1 Enabled by default Remote Processes: 11 Enterprise Policies: Inactive Google Location Service Key: Found Google Safebrowsing Key: Found Mozilla Location Service Key: Missing Safe Mode: false Memory Size (RAM): 31.1 GB Disk Space Available: 383 GB

When watching twitch and I open another tab, the new tab is very slow to open a web page and sometimes wont open at all just keeps scrolling. Any suggestions how to solve this problem?? I tried with Opera and it doesnt have that problem?? Dont want to give up on Firefox as I like it the most. Any help much appreciated.

BR

Mika Nyqvist