How Do I Control the Brightness of an External Monitor In macOS?
A free utility can help
If you use your Mac in combination with an external display, you may have noticed that you can't adjust the display's brightness in most cases. So the only option is to use the buttons on the monitor itself, where you have to manually click through everything to change the brightness.
Unfortunately, this is one of the fundamental flaws of the macOS operating system. Competing Windows, on the other hand, has no such problem and can handle brightness adjustments natively. As we mentioned above, the inability to control the brightness of an external display is one of macOS’ fundamental flaws. But we could find more.
At the same time, Apple computers lack, for example, a volume mixer, the ability to record system audio + microphone simultaneously, and many others. But now let’s stay with the mentioned brightness. This whole problem has a simple solution. And you’ll be pleased to know that it’s open-source and completely free.
MonitorControl is the perfect solution
If you would like to control the brightness of your monitor or the volume of its speakers directly from the system, then the MonitorControl app can help you out. As we mentioned above, this is an open-source utility that you can download for free directly from the developer’s Github.
To download it, go to this link and at the bottom of the Assets section, click on MonitorControl.4.1.0.dmg. In this case, however, you must have a Mac running macOS 10.15 Catalina or later. Then install the app (move it to the Applications folder), run it, and you’re practically done. After that, you must enable the app to use the keyboard (crucial for control).
You can then use the classic F1/F2 keys to control the brightness of the external display or even the volume. Alternatively, you can click on the utility from the top menu bar and edit it. But let’s have a very brief look at how it works.
Most modern LCDs have the DDC/CI protocol, allowing you to control the monitor via DisplayPort, HDMI, USB-C or VGA hardware. Whether it’s brightness or volume. In the case of Apple/LG displays, it is even a native protocol.
Nevertheless, we do run into some limitations. Some displays use an alternative MCCS over USB or rely on a custom protocol, making it impossible to control them in the same way. This is particularly the case with EIZO monitors. In this case, therefore, only software brightness adjustment is offered.
At the same time, the HDMI connector on the Mac mini with Intel CPU (2018) and Mac mini with M1 (2020) prohibits communication via DDC, which again limits the user to software-only control.
Fortunately, this can be circumvented by connecting the display via the USB-C connector (USB-C/HDMI cables usually work). The same limitation applies to DisplayLink docks and reducers. These don’t allow you to use the DDC protocol on Macs.
A reliable way to control the brightness of an external monitor
So if you’re looking for a reliable way to control an external display's brightness without having to reach for the monitor buttons constantly, MonitorControl seems like the perfect solution. What’s more, the app offers extensive customisation options.
For example, you can change keyboard shortcuts and many other settings. I like that it’s extremely easy to control the brightness on both the MacBook display and the external monitor.
In this case, the keyboard shortcuts adjust the screen brightness on which you currently have the cursor. But you can also set the brightness always to be the same on both displays. In this case, it depends on each user and their preferences.
Thank you for reading this article! If you enjoyed it, please leave me 👏🏻 and follow me for more content like this! 😊👍
