topic Re: Increased memory useage and Youtube pages lagging after today's update in Discussions

Increased memory useage and Youtube pages lagging after today's update

Maz — Wed, 30 Sep 2026 16:22:03 GMT

Hi all,

After Firefox updated today I noticed that Youtube pages have become slow to respond.

Also memory usage seems to have increased to 5 GB. Anybody else noticed this?

Thanks in Advance

Maz

Re: Increased memory useage and Youtube pages lagging after today's update

dftf — Wed, 30 Sep 2026 16:55:03 GMT

Not seeing that here: Firefox currently using around 1.5GB, according to the Processes tab in Windows Task Manager.

In Firefox, try going to Menu -> More tools -> Task Manager , click the Memory column heading to sort highest first and see if a particular site is causing it. Or maybe it's an extension you use?

Re: Increased memory useage and Youtube pages lagging after today's update

alison — Wed, 30 Sep 2026 17:37:40 GMT

Having that same problem. I switched to DuckDuckGo til they fix it.

Re: Increased memory useage and Youtube pages lagging after today's update

wp — Wed, 30 Sep 2026 18:50:46 GMT

Same problem here. Youtube is unusable for me. Also crashes tabs.

Re: Increased memory useage and Youtube pages lagging after today's update

Redgdk — Thu, 01 Oct 2026 03:55:26 GMT

Same here, switched to Brave

Re: Increased memory useage and Youtube pages lagging after today's update

Bulathsinhala — Thu, 01 Oct 2026 06:14:30 GMT

The new update is extremely slow, YouTube is basically unusable. The CPU usage is moving between 100% - 49%. This update Suck.

Re: Increased memory useage and Youtube pages lagging after today's update

dftf — Thu, 01 Oct 2026 07:01:04 GMT

In Firefox, when you're having an issue, go to Menu > More Tools > Task Manager
Click on the "Memory" or "CPU" columns to sort highest-first
Is a particular website causing high Memory or CPU?

Or if "🧩 Extensions" is the line causing either, one of your extensions may be the issue
Try going to Menu > Extensions and Themes > click the ⚙ icon > Check for Updates

Re: Increased memory useage and Youtube pages lagging after today's update

dftf — Thu, 01 Oct 2026 07:01:36 GMT

In Firefox, when you have an issue, go to Menu > More Tools > Task Manager
Click on the "Memory" or "CPU" columns to sort highest-first
Is a particular website causing high Memory or CPU?

Or if "🧩 Extensions" is the line causing either, one of your extensions may be the issue
Try going to Menu > Extensions and Themes > click the ⚙ icon > Check for Updates

Re: Increased memory useage and Youtube pages lagging after today's update

dftf — Thu, 01 Oct 2026 07:03:24 GMT

I'm having no issues with YouTube here, and only use the uBlock Origin extension
If you use other extensions, one of them may be causing the issue
Try going to Menu > Extensions and Themes > click the ⚙ icon > Check for Updates

Re: Increased memory useage and Youtube pages lagging after today's update

dftf — Thu, 01 Oct 2026 07:04:14 GMT

Try going to Menu > Extensions and Themes > click the ⚙ icon > Check for Updates
It could be an issue with one of your extensions

Re: Increased memory useage and Youtube pages lagging after today's update

dftf — Thu, 01 Oct 2026 08:24:22 GMT

I can see a number of reports about this on Reddit, and here are the things people here can try:

1. Turn off the Ghostery extension for YouTube
Many people say it was this extension that was causing them the issue

2. Clear the cache for YouTube
When you're on the YouTube site, click the shield (🛡) icon in the web-address bar, then click "Clear cookies and site data", then Clear Data

3. Turn-off any custom filters if you use uBlock Origin
Click the uBO shield, then the cogs to go into the settings. On the "Filter Lists" screen, make sure you're only using the default filters, not things like "uBlock filters - Experimental". If you've subscribed to any of your own blocking-lists, try unchecking them also. That has worked for some people.

Please check those things and see if YouTube remains an an issue after.

Re: Increased memory useage and Youtube pages lagging after today's update

Bulathsinhala — Thu, 01 Oct 2026 10:52:08 GMT

Seems to be the "Ghostery" extension. I de activated it and the CPU usage went down.

Re: Increased memory useage and Youtube pages lagging after today's update

Maz — Thu, 01 Oct 2026 13:15:47 GMT

Thanks to everyone for confirmation/solutions. I've disabled Ghostery and that seems to have worked for me.

Maz

Re: Increased memory useage and Youtube pages lagging after today's update

Redgdk — Sat, 03 Oct 2026 10:17:49 GMT

Sorry
Why should i do that they change it and screw it up for me

Re: Increased memory useage and Youtube pages lagging after today's update

benalvi — Sat, 03 Oct 2026 14:32:37 GMT

Same thing happened to me and Ghostery was the culprit too. Disabling it just for YouTube fixed the lag right away. Glad the OP confirmed it, this thread will probably help a few others.

Re: Increased memory useage and Youtube pages lagging after today's update

dftf — Sun, 04 Oct 2026 11:10:40 GMT

It may not be a Mozilla screw-up.

Loads of people on Reddit have all said YouTube has become insanely slow and was crashing the tab for them... turns out its an issue in the Ghostery extension. Disabling that on the YouTube page fixed the issue.

It just happened their mess-up coincided with the updated Firefox 157.0 release, so many people put the blame on that instead.

If you suddenly get issues on major-websites, it's nearly always going to be an extension.