Screen flickering after updating to Mac OS Tahoe

I have a similar setup:

Mac Mini M4 Pro with a Dell monitor.

I'd like to share how I fixed the flickering issue.

The flickering is acknowledged by Dell and other vendors like BenQ—even with newer monitors—as something they cannot resolve on their end.

The root cause is Apple's display controller, which applies temporal dithering by default to simulate smoother gradients, even on high-quality monitors. This causes not only discomfort for sensitive users but also severe flickering in some setups, leading to eye strain and usability issues. macOS offers no built-in way to disable it permanently. That would be very nice if Apple would implement this feature.

The solution:

To disable dithering permanently on a Mac Mini M4, you can use a tool like Stillcolor to override the display controller's default behavior and set it to launch at login. Without third-party tools, macOS does not offer a built-in method to persistently disable dithering across reboots.

I have installed the tool with brew. Have a good day.

[Edited by Moderator]

I have MBP 2019. I changed Display refresh rate from 60Hz to 59.94Hz. Flickering has stopped.

so glad I'm not the only one. Before updating to Tahoe, I never had an issue once. Im on the M4 MacBook Air. Since I've updated, my display started doing this flickering or as I call it, "Blinking" as if it's trying to auto adjust the brightness. Turned off True Tone, auto brightness, etc. Nothing works, and this came from apple support. I think it's a bug and it's getting really annoying to look at.

I have this issue with an M1 MacBook Pro and Studio Display. I tried section77's solution, which is to install and use Stillcolor, and that worked. If you have Homebrew installed, you can install it via CLI using this command:

brew install --cask stillcolor

It installs it in the Applications folder. When you run it, it appears in the menu, and these settings fixed it for me.

vbcbb wrote:

After updating to Mac OS Tahoe sometimes I get a slight flickering for 1-2 minutes. I use an Macbook Air M3 and I am connected to an external monitor using a Type C - Display Port cable. Before the update I didn't have any of these problems.

Did someone had this problem?

unplug all non-essential peripherals when testing.

If no issue on the internal display, I would think about the cable or Monitor as the issue and go from there

Adding to this thread. My screen flickers for some apps. Right now only for Calendar. Flickering is around the "buttons" in the app. My thinking is that Glass is confusing the heck out of the display controller (assuming display controller means the process that 'writes' out the display). I don't have this problem with Safari.

So, tossing it out there wondering how much of this bug is about Glass.

Same here on Apple Studio M4Max, Contacts App looks horrible, my screen looks like the backlight is falling apart. Only it isn't. It is a bug only happening after Tahoe upgrade.

Same issue on my Maccbook Pro M4. The issue is on my Macbook Screen itself and it only happens when the fans are at full blast.

Thank you section77 for your explanation. It sheds a new light on the cause of the issue and explains why most likely not the hardware is the cause of the flickering, but the Tahoe update, making a lot of monitors flickern after updating to Tahoe. It would be nice if a list of compatible monitors would show up. To be honest I was already in the process of looking out for a new monitor to make use of the better refresh rates this Apple Studio offers. But I will hold that of for now until this issue will be resolved. I am reading more and more reports. So something has to be done.

i have a m1 air and it also has same issue

I am also facing this on my macbook m1 pro 14.

Too add on i am not using an external monitor, i am talking about the actual MacBook display itself!

With so many people confirming the flickering and even reports why the flickering occurs I do not understand you blaming the cables. This is not very helpful in resolving the undeniable issue.