Firefox Community Forum

I get REAL tired by the amount of resources Firefox eats up with each open window. For whatever reason, having multiple windows open prevents Facebook from loading. I'll get 1 story and a "shorts" bar but THAT'S IT. Even clicking the story to rate or comment does nothing. If I start to delete windows; it will decrease the memory usage and then it will open.

However, I DO NOT WANT TO CLOSE MY WINDOWS IN ORDER TO OPEN FACEBOOK! Firefox should not be eating up that many resources. The open windows are of text and/or picture archives. There is no sound or video playing in the multiple windows open. My system literally has 128 gigs of ram memory so it seems very odd to me that Firefox is using between 11-13% with nothing running in the 15 windows I have open.

Firefox dropdowns, menus and popup menus do not appear after resume from suspend on Ubuntu 22 or 24 This has been happening for only the last few weeks. Even dropdowns on web pages do not appear. I can click the dropdown and cursor down then hit ENTER to change a dropdown's value but I cannot see anything while I'm doing it. On the menus, I can use hotkeys if I remember them but the menus themselves do not appear. Right-clicking to get a context menu also does nothing but it behaves like it did. If I right click something, nothing changes on screen but if I then click another link or button, the first click is swallowed to dismiss the non-existent popup.

Other apps on the system work fine including Chromium browser.

This only occurs if I start Firefox then suspend the machine and then resume from suspend. After resume, the menus, dropdowns and popups no longer appear.

I am running Ubuntu 24.04.4 LTS on a Dell Optiplex 3050, Core i3-7100x4 , 16 GB ram, Intel HD graphics 630 (KBL GT2), Gnome 46, Wayland windowing system.

I tried Firefox safe mode, clearing the caches, etc. Nothing worked.

I am on a new PC with Windows 11, using 4 monitors. I keep trying to figure out what is making my mouse and sometimes the keyboard behave sluggish (freezes for a moment). I have takes all suggestions that AI has suggested but it is still happening. Do you have any thing for me to try? It appears to be only when Firefox is running.

• • Background:**

I'm a senior software engineer running Firefox Developer Edition on a Linux machine with 8GB RAM. I have Fission architecture (site isolation) enabled, which I understand is now the default since Firefox 95+.

• • The problem:**

When I open 20 or more tabs across different domains, Firefox's memory consumption scales dramatically — often reaching 4–6GB of RAM for what should be lightweight browsing sessions. This is significantly higher than what I observed before Fission was enabled.

• • What I've already tried:**

- Disabled hardware acceleration → no significant improvement - Set browser.tabs.unloadOnLowMemory to true → partial relief

 but tabs reload constantly, disrupting workflow

- Reduced content.notify.interval → marginal improvement - Tested with all extensions disabled (safe mode) → RAM usage

 still high, confirming it's not extension-related

- Checked about:memory → large number of separate

 "Web Content" processes, one per origin as expected with Fission

• • What I'm trying to understand:**

1. Is there a way to set a maximum process count cap for Fission

  without fully disabling site isolation? I found 
  dom.ipc.processCount but changing it doesn't seem to affect 
  Fission's per-origin process spawning behavior.

2. Is browser.tabs.min-warm-process-count a relevant setting here

  and what is the safe range to modify it?

3. Does Firefox have a built-in memory pressure threshold where

  it automatically consolidates processes — similar to Chrome's 
  memory saver — and if so, which about:config keys control it?

• • Environment:**

- Firefox Developer Edition 151.0b10 - OS: Ubuntu 24.04 LTS - RAM: 8GB - Fission enabled: confirmed via about:support - Extensions: disabled for testing

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!!!

Firefoxa używam od lat ale ostatnio strasznie mnie wkur....bo kilka aktualizacji zepsuło ten program, co aktualizacja to gorzej z wyszukiwaniem i pobieraniem np. zdjęć, nie raz nie da się odświeżyć strony, nawet wyczyszczenie historii nie pozwala na nowo wczytać strony zapisanie kolejnego zdjęcia o tej samej nazwie nie pozwala wpisać np; image 1, 2, 3 itp wklejając np: image okno jest nie aktywne by wpisać 1,2, 3, itp; trzeba czekać aż Firefox się namyśli i pozwoli dokończyć wpisywanie, szlag trafia człowieka przy takim działaniu. te wasze aktualizacje gdyby rozwiązywały problemy nie byłoby tyle poprawek Np 150.01, 150.02, 150.03 myślę, że następna aktualizacja 151 będzie bez błędów i wyeliminuje obecne bo inaczej będę musiał zmienić przeglądarkę. I jeszcze jedno wyszukując zdjęcia są one zamazywane i wielokrotnie pojawia się informacja że zmieniliście mi ustawienia przeglądarki (włączony filtr) wyłączam go ale nie ma opcji zapisania ustawień i za jakiś czas sytuacja się powtarza, zróbcie coś z tym i nie decydujcie za mnie co mam włączone a co nie. Tak samo jest z motywami niektórych nie da się usunąć a zaśmiecają kompa. Jurek

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.

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?