1999129 - High memory usage of FF 144.0.2

Status: UNCONFIRMED

(Core :: Performance: Memory, defect)

Description

[Stefan Matthäus]

Attachment: Zwischenablage_11-09-2025_01.jpg

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0

Steps to reproduce:

Reopened Firefox after last use of the computer, starting other applications, having some breakfast, returning to the computer. Firefox is set up to reponeed three windows with approx 25 tabs in total.

Actual results:

Computer mostly unresponsive, managed to open taskmanager after 25 minutes of reaction time. Making unbelieveable screenshot, see attached. My Win 11 PC has 32 GB of RAM and all was used by Firefox! And this is the 3rd time that this behaviour happened in the past three weeks.

Expected results:

Computer useable. Needed to reset and reboot again.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Performance: General' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Stefan Matthäus]

Upgraded to FF 145.0 and now it looks much better, in total ff only uses 2 GB of ram with the same tabs and windows as before.

tasklist | find /i "firefox"
firefox.exe 22052 Console 1 422.192 K
firefox.exe 28268 Console 1 105.324 K
firefox.exe 17316 Console 1 18.724 K
firefox.exe 26144 Console 1 29.172 K
firefox.exe 24844 Console 1 248.980 K
firefox.exe 4016 Console 1 96.936 K
firefox.exe 6176 Console 1 97.708 K
firefox.exe 14572 Console 1 80.228 K
firefox.exe 18732 Console 1 74.908 K
firefox.exe 2256 Console 1 17.416 K
firefox.exe 11192 Console 1 73.016 K
firefox.exe 19964 Console 1 85.924 K
firefox.exe 29528 Console 1 67.796 K
firefox.exe 26336 Console 1 76.100 K
firefox.exe 19932 Console 1 106.812 K
firefox.exe 3228 Console 1 94.340 K
firefox.exe 15064 Console 1 72.152 K
firefox.exe 23568 Console 1 810.864 K
firefox.exe 12820 Console 1 72.032 K
firefox.exe 20944 Console 1 74.868 K
firefox.exe 29896 Console 1 96.424 K
firefox.exe 30152 Console 1 95.140 K
firefox.exe 30340 Console 1 71.728 K
firefox.exe 30096 Console 1 98.448 K
firefox.exe 18880 Console 1 68.728 K
firefox.exe 1788 Console 1 154.536 K
firefox.exe 5604 Console 1 72.444 K
firefox.exe 5680 Console 1 70.552 K
firefox.exe 31108 Console 1 77.444 K
firefox.exe 31412 Console 1 86.088 K
firefox.exe 30784 Console 1 115.124 K
firefox.exe 16264 Console 1 110.736 K
firefox.exe 33336 Console 1 85.720 K
firefox.exe 31088 Console 1 86.924 K
firefox.exe 25460 Console 1 18.524 K
firefox.exe 34792 Console 1 87.296 K
firefox.exe 33920 Console 1 96.372 K
firefox.exe 32772 Console 1 53.108 K
firefox.exe 24168 Console 1 48.340 K
firefox.exe 34076 Console 1 48.064 K
firefox.exe 28348 Console 1 45.980 K
firefox.exe 30492 Console 1 55.696 K
firefox.exe 33112 Console 1 48.988 K
firefox.exe 31872 Console 1 69.120 K
firefox.exe 33020 Console 1 48.048 K
firefox.exe 33332 Console 1 34.540 K
firefox.exe 13544 Console 1 34.644 K
firefox.exe 22512 Console 1 34.552 K

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:bas.schouten, could you have a look please?

For more information, please visit BugBot documentation.

Comment 4

[Stefan Matthäus]

Unfortunatelly it happens again, now with 145.0.2.

When closing firefox over the hamburger menu a lot of ff tasks stay active and still 32 gb of RAM are used. When killing over taskmanager then immediatelly 27 gb of ram are free.