1964744 - high cpu memory youtube

Status: UNCONFIRMED

(Core :: Performance: Memory, defect)

Description

[pbzin]

Attachment: Firefox 2025-05-06 13.15 profile.json.gz

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:140.0) Gecko/20100101 Firefox/140.0

Steps to reproduce:

youtube open

Actual results:

high memory and cpu usage at all times

Expected results:

lower memory and cpu usage, especially after loading

Comment 1

[pbzin]

When used with the Chrome Mask extension, the memory and cpu usage is low, and when YouTube is loaded it returns to an even lower usage, that is, with this extension it seems to work normally, without it the memory and cpu usage is high and even with no video running the usage remains high and does not stop.

Comment 2

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

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

For more information, please visit BugBot documentation.

Comment 3

[Justin Link]

pbzin: Could you capture a memory report (go to 'about:memory' and select 'Measure and Save') and upload it to this bug the next time that you see this happening? Youtube is, in general, fairly memory-intensive so this data would be useful to be able to quantify how much is actually being used.

It is certainly interesting that you are seeing lower memory and CPU usage when using Chrome Mask. Does that actually work well/properly for you? The author of that extension even specifically says that they don't think it should be used for YouTube. If enabling that extension breaks some functionality then that could explain why the memory usage is lower.

That having been said, the profile does show that something is wrong - we spend the entire 5.7s of that profile (and possibly even more than that because the jank marker is 14.5a long) in an incremental CC. That would seem to imply either some kind of leak or "legitimate" heavy memory usage by the site.

The first step right now though would be to verify if you're still able to see the problem with latest Firefox and the current version of YouTube and to get a memory report (see instructions in first paragraph) if you are.