macOS Tahoe 26.3 Beta 1 - Bug fixes, changes, and more

[WilliApple]

Release Date ― 15 December 2025
Build Number ― 25D5087f
Apple Silicon System Firmware Version ― 13822.80.393
T2 BridgeOS System Firmware Version ― Pending

---

New Features & Changes (Found something new? Please press "Edit" on the bottom of this post and add it here)
Resolved Issues
New Issues
(If you are encountering any issues, please press "Edit" on the bottom of this post and add it here)
Remaining Issues
Untested Issues

• On non notched devices, the volume indicator may have excessive padding in full screen (Present since 26.2 Beta 3)
• Alarms may not play when your display is asleep for a long period of time (FB10086690)
  • Workaround: Make your display not fall asleep in Settings > Lock Screen > Turn display off on ____ when inactive. You can turn your brightness off.
  • Issue present since macOS 13.0
• Dictionary toolbar does not have the blur effect for content that scrolls (FB20961118; present since 26.0)
• Desktop wallpaper image fidelity cut to 50% if using a non-Apple supplied photo (eg. from Photos / a file - bug introduced in 26.2). FB21259665

Additional Notes

• Please know, Memory Management has always been an issue on any OS (not just Apple's). If you believe there is a Memory Leak, please go to the Apple Menu > Restart > Restart to fix it.
• When a new macOS release comes out, all issues automatically go to "Untested Issues" until they are moved by someone. Issues that stay in Untested for 3 releases (beta or smooth) will be removed from all future threads. When there is a new macOS release, please be sure to let us know about the issue's status by moving it to either "Remaining Issues" or "Resolved Issues"
• macOS 26 Tahoe will be installed via a Delta Update in System Settings. Please be aware about this, as the update won’t install with an installer.
• macOS 26 is officially supported on the following devices. If your device is not listed below, it has unfortunately been dropped by Apple. Any efforts of trying to get your Mac running macOS 26, including bugs should be discussed in this thread.
  • MacBook Air: M1, M2, M3, M4
  • MacBook Pro: 2019 (16 Inch only), Intel 2020 (4 thunderbolt port only), M1, M1 Pro/M1 Max, M2, M2 Pro/M2 Max, M3/M3 Pro/M3 Max, M4/M4 Pro/M4 Max, M5
  • Mac mini: M1, M2/M2 Pro, M4/M4 Pro
  • iMac: 5K 2020, M1, M3, M4
  • Mac Pro: 2019, M2 Ultra
  • Mac Studio: M1 Max/Ultra, M2 Max/Ultra, M3 Ultra, M4 Max
• macOS Tahoe 26.3 Release Notes
• macOS Tahoe Overview
• Apple Security Updates
• Become an Apple Beta Tester
• Full Installer (Direct Download)

 

[Adora]

 

[Adora]

Everything is different! 🙃

 

[Adora]

Edit: It's settling...

Edit 2: Done, but I don't know what is using the GPU that much. It's jumping between about 25 and 35% at the moment. In 26.2 it always jumped between 0 and 20%.

 

[Adora]

Nothing new here.

 

[Samsonnnnnn]

How's the performance so far?

 

[Ethan.Albano]

Has the music app changed at all? That was probably the biggest difference between 26.1 and 26.2.

 

[Adora]

How's the performance so far?

I couldn't test much yet. Had to sleep and just woke up. 😐 After a reboot I just did I got that high CPU usage again but it settled much faster and GPU usage is lower now than I described before.

Has the music app changed at all? That was probably the biggest difference between 26.1 and 26.2.

Mine is empty at the moment and I didn't use it much before. I can only give you a screenshot.

 

[Ethan.Albano]

Mine is empty at the moment and I didn't use it much before. I can only give you a screenshot.


View attachment 2588314

Looks about the same as it did before! Maybe the Liquid Glass is slightly more glassy with how red it looks? Who knows 🤷‍♂️

Most of the changes in 26.2 came in the fullscreen view and MiniPlayer - I’ll get around to testing it out soon. The changes look good, but not sure I love the functionality of them, specifically with the MiniPlayer.

Thank you!

 

[Adora]

Mac mini just woke up with a black screen and there was only a mouse cursor that could be moved. I had to force turn it off with the power button. This never happened before the update.

 

[Adora]

Memory usage is now up to 80% with only a few YouTube tabs open and the browser is using "only" about 5 GB. In the 26.2 Betas and final version it never went over about 55%.
I already rebooted 4 times since updating and it always fills up the memory very quick. I know it doesn't matter if the pressure is low, but it's strange. Cashed files had been more than double before and memory used much less than now.

I wonder how this is looking like with only 16 or even 8 GB of RAM.

When I use a memory cleaner what I normally don't do it looks like that:

It went down from about 80% to about 60% what still is more than before the update and it made the pressure higher. Seems it compressed a big part of app memory.
That cleaner didn't change much when I tested it in the 26.2 Betas and RC/final, maybe total memory usage was going down from 55% to 51%.

 

[Adora]

Is this new? I never turned it on but it was and after turning if off it's still shown as on here:

 

[yukari]

Memory usage is now up to 80% with only a few YouTube tabs open and the browser is using "only" about 5 GB. In the 26.2 Betas and final version it never went over about 55%.
I already rebooted 4 times since updating and it always fills up the memory very quick. I know it doesn't matter if the pressure is low, but it's strange. Cashed files had been more than double before and memory used much less than now.

I wonder how this is looking like with only 16 or even 8 GB of RAM.


View attachment 2588572


When I use a memory cleaner what I normally don't do it looks like that:

View attachment 2588588

It went down from about 80% to about 60% what still is more than before the update and it made the pressure higher. Seems it compressed a big part of app memory.
That cleaner didn't change much when I tested it in the 26.2 Betas and RC/final, maybe total memory usage was going down from 55% to 51%.

Here is memory usage on my 16 GB Mac Mini

Top: MacOS 26.2
vs
Bottom: 26.3 beta 1

Same conditions: using Brave browser and Activity Monitor

 

[ikaka]

Can someone check if spotlight math is fixed?

 

[slomtbr]

Can someone check if spotlight math is fixed?

 

[matthew28845]

Is the issue with the dictionary app title bar blur not existing fixed?
Here is how it looks on 26.2

 

[matthew28845]

Also, the weirdly stretched out search icon in Console (visible in this screenshot in 26.2, compare it with the screenshot in my last post)

 

[Adora]

Full Installer 26.3 Beta (25D5087f):

https://swcdn.apple.com/content/downloads/08/08/089-61660-A_BDNQD10OAE/dxyekmr1r0ragzx9rhh12naryoq3jkb6q7/InstallAssistant.pkg

----

And again I am downloading 15.7.4 RC1 (24G503) to downgrade. Maybe my planned downgrade is happening this time. 🙈

https://swcdn.apple.com/content/downloads/44/19/089-61098-A_KZDXRCILYT/7ava2o9kiinxwozfdlszr5dwu6skwlkscg/InstallAssistant.pkg

 

[Adora]

Here is memory usage on my 16 GB Mac Mini
View attachment 2588736View attachment 2588737
Top: MacOS 26.2
vs
Bottom: 26.3 beta 1

Same conditions: using Brave browser and Activity Monitor

Seems this process is somehow going crazy on my Mac. I don't even use Shortcuts on any device. I forced quit all of them. But I think they will come back after a reboot. I found there were problems with it before causing high CPU usage but it was 0.0% here. Only taking up memory. There were even some more bu all didn't fit on the screenshot.