YouTube extremely laggy on macOS in Brave (scrolling and video stutter, works fine in Safari)

Brave Browser Web Compatibility
1

YouTube extremely laggy on macOS in Brave (scrolling and video stutter, works fine in Safari)

Description:

I am experiencing severe performance issues on YouTube when using Brave on macOS. The problem affects the overall user experience, including scrolling, UI responsiveness, and video playback.

The same issue also occurs on Google Chrome, which suggests that the problem may be related to Chromium rather than being specific to Brave.

Details:

  • Scrolling on YouTube is noticeably laggy and stutters frequently

  • Video playback is not smooth and may drop frames

  • General UI interactions (hovering, opening menus, switching videos) feel delayed

In contrast, YouTube works perfectly fine on Safari on the same machine, with smooth scrolling and playback. This indicates the issue is specific to Chromium-based browsers on macOS.

Additional Notes:

  • Issue persists even after disabling extensions

  • Brave Shields ON/OFF does not resolve the issue

Summary:
YouTube performance is significantly worse on Brave (and Chrome) compared to Safari on macOS, affecting both scrolling and video playback.

2

If same happens on Chrome, its likely that your CPU struggles

3

Then why that happens, two weeks ago it was all good.

And again why the problem isn’t happening on safari browser

4

Check for how many tabs you have on those browsers, also check how much those browsers eat of your CPU, tell me what Device and Device’s OS you use.

5

Only the YouTube tab is affected. I also checked Activity Monitor to see how much CPU and GPU are being used, and both were mostly idle (around +90% idle), so it doesn’t seem to be a hardware issue.

I’m using macOS Tahoe on a MacBook Pro 2019, so it’s not low-end hardware. At this point, I believe it’s 100% a software-related problem.

Interestingly, when I connect my Mac to an external display, the issue disappears — YouTube works smoothly as expected. This makes me think the problem is related to GPU switching. When I connect to an external screen, macOS automatically switches to the higher-performance GPU, but when I disconnect it, it falls back to the lower-power GPU, which might be causing the lag.

6

So strange,

I digged up from Gemini:

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The 2019 MacBook Pro uses two GPUs: an integrated Intel UHD Graphics (low power) and a discrete AMD Radeon (high power).

​The External Display Factor: When you plug in an external monitor, macOS forces the high-performance AMD GPU to activate because the physical video output ports are often wired directly to it.

​The Chromium Problem: Browsers like Brave and Chrome use the Chromium engine, which handles hardware acceleration differently than Safari. On the internal display, macOS tries to save power by staying on the Intel GPU. Chromium often struggles to utilize the Intel chip’s video decoding (VP9/AV1 codecs used by YouTube) as efficiently as Safari, leading to the lag and UI stutter you’re seeing.

​The “Tahoe” Factor: Since the user mentions macOS Tahoe (a future/beta version in this context), it’s likely that the display drivers for older Intel-based hardware haven’t been fully optimized yet, exacerbating the “stutter” during GPU handoffs.

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Solution mentioned is:

The simplest way to verify this is to stop macOS from switching to the low-power chip:

​Go to System Settings > Battery > Options.

​Uncheck “Automatic graphics switching”.

​Note: This will decrease battery life but should provide the same “smoothness” as the external monitor.

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Try it, otherwise im powerless since its not even Windows or Linux…

7

I suspect its also manageable by tweaking experimental flags for Chromium Browsers, but also more dangerous.