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.

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for your reference I actually downgraded to sequoia 15.7 from Tahoe - brand new MBA m4 from last Nov, no external monitor and screen flickers after I installed Tahoe, on every Tahoe versions I tried. Finally decided apple should stop harming my eyes. I backed up all my files, did a factory reset, transferred everything from my MBA m1, then copied the backup files over. I am a software developer, a good working screen that doesn't flicker, either I can see the flickering, or just creating eye strain, is not acceptable.

I had this issue with an Apple Studio Display connected to a 2021 M1 Pro MacBook Pro via a Thunderbolt cable. This was mainly between switching applications or most severely during conversation switching in Messages. I noticed that this got worse with backgrounds set up for contacts.

To resolve I switched from 2048 x 1152 to the default 2560 x 1440. I imagine since it's using a fixed refresh rate rather than the variable one used at the scaled resolution? There might be a better fix, but that's the easiest one I came up with.

Cheers

Critchlowr wrote:

To resolve I switched from 2048 x 1152 to the default 2560 x 1440.

I imagine since it's using a fixed refresh rate rather than the variable one used at the scaled resolution? There might be a better fix, but that's the easiest one I came up with.

Good computing Critchlowr !

You don't say what monitor, nor how it is connected to your mac. In recent versions, macOS has become quite sensitive to the quality of cables, there are plenty of reports here saying that switching to high quality cable has fixed display issues. This could be the case, or not, of course.

FWIW, I use an 1080p HD Samsung display connected to my MacBook Pro at home, and an older display connected to either the MBP or an a M1 Max Mac Studio at work, and have never experienced screen flickers.

Maybe these only happen in higher resolution displays (for which high quality cabling seems to be a must)?

for your reference I downgraded from Tahoe. I have a MBA m4 purchased last Nov, migrated my previous M1 to this new laptop, things start to fall apart when I installed Tahoe, laptop screen had noticable flickers, and caused eye strain. I tried several Tahoe versions and finally decided this doesn't worth it.

I backed up all my files, did a factory reset to the m4, transferred again from m1, then copied the files over. I am staying with Sequoia until apple becomes responsible and provide a real solution to this problem.

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.

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Same here. My company issued MBP M4 Pro, my personal Mac Mini M2 and M4 all have the flickering issue (USB-C connection to external monitor) after upgraded to Tahoe. HDMI works fine.

Hope Apple can address this issue soon.

My M3 Max MBP connected to a Studio Display started flickering after updating to Tahoe. The best way to recreate is by switching from dark to light screen content. It seems like the backlight management gets confused and commands bright / dim / bright / dim a few times before resolving. It is not subtle and 100% started after the Tahoe update.

It's not limited to external display, flickers on laptop display, too. After reading this entire topic and doing extensive research online, my best bet is Tahoe display driver cannot properly handle fast screen changes, i.e. video, window move, etc. I have a M1 MBA before I bought my M4 3 months ago, the M1 was not bugraded to Tahoe and is fine. M4 is bugraded from Tahoe 26.1 and then bugraded to 26.2 due to flickering, and still flickers, no external display involved.

This kind of bugs is not easy to reproduce, doesn't always happen. I used to be a driver / kernel developer, would be nice if Tahoe was able to spit out some error log instead of pretending no biggie.

I currently have an 2024 iMac running on Tahoe 26.3.1. I had this flickering problem, especially around the time when the outside light was changing, even if clouds flew over and disappeared. With the latest OS version, 26.3.1, I'm happy to say this problem went away.

It sounds like there are multiple different kinds of flickering going on as people are reporting here.

I changed to a different resolution that doesn't show flickers or that i don't notice. Now I have a big screen with bigg fonts :/

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