Dimming an external non-Mac monitor

I’ve started using an external monitor with my Mac a while ago and it’s always been bothering me that at night while my Mac’s screen does dim, the external monitor doesn’t.

A few days ago, I decided to see if there was an app that could help me sync the dim level of my external monitor with the MacBook Pro’s built-in monitor. I looked at SmartSaver, Shades, Screen Shades, Shade Control and a bunch of other apps and none of them seemed to be able to do this simple task. What’s more, most of them seemed to be discontinued and/or haven’t been updated in years.

So I decided to see if there’s anything I can do about it. All I needed to do was read the main monitor’s dim level and overlay a transparent black window with inversely related alpha value over the external screen.

The whole thing fit into less than 100 lines of code, though I also added the ability to automatically start on startup.

I made it open source, named it Dimlink, and you can contribute at GitHub. Or just download it.

If you have any suggestions, comments or questions, feel free to message me or open an issue on GitHub.