Plugging an external monitor into Windows 11 hides one of its most essential controls: the brightness slider. While the slider is still visible, it only controls your primary display, leaving you unable to adjust your external screen. It’s one of the most frustrating quirks of using multiple monitors on Windows 11. Fortunately, a free, open-source tool called Monitorian solves this exact problem and is a must-have for any multi-monitor setup.
Why Windows Ignores Your External Display
The DDC/CI piece nobody talks about
Notably, Windows 11 does not show you a brightness slider for the connected monitor, which is not a bug, but designed in this way. Microsoft’s own support page confirms plainly that you won’t see the brightness slider on Windows PCs using an external monitor. You need to reach for the buttons on the monitor itself instead.
Windows was built to control the backlight on internal laptop panels, not the electronics inside a separate display sitting on your desk. Here is where it gets interesting, though. Most modern monitors actually can be controlled by software. All they need is to be able to talk to your PC using a protocol called DDC/CI (Display Data Channel/Command Interface).
For those who don’t know, it is the same channel your monitor uses to report its capabilities to Windows. The catch is that Windows itself never built a front-end for it. So this means that the hardware support is sitting right there, but Microsoft just never wired up a slider to use it. This is exactly the gap that apps like Monitorian exist to close.
Monitorian is here to save your day
It lets you set a custom adjustable range
Monitorian is a free, lightweight, and open-source tool built by developer emoacht. It has been actively maintained since 2017 and has helped several users configure a multi-monitor setup to adjust the brightness of their connected displays without pressing physical buttons. It is one of the best multi-monitor tools you should definitely use.
Instead of a Settings menu, Monitorian lives in your system tray. You need to click the icon, and you get a slider for every connected display, which also includes laptop panels, right there in one small fly-out window. If you run two, three, or four monitors, you can drag each slider independently.
If you want to have individual control over each monitor, then you can turn on the “Move in unison” toggle, so that every screen brightens or dims together with a single drag. I prefer keeping mine synced most days since my monitors sit side by side, but I break unison mode when sunlight hits at a different angle on my monitors, and I need one screen dimmer than the rest.
The best thing about Monitorian is that you’re not stuck with the default 0 to 100 range. Monitorian lets you set a custom adjustable range for both brightness and contrast per monitor. This comes in handy if your display’s lowest setting is still too bright for a dark room, or its highest doesn’t quite max out.
- OS
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Windows
- Developer
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emoacht
Monitorian is a lightweight Windows utility that lets you quickly adjust brightness and contrast for multiple internal and external monitors simultaneously or individually, with optional advanced hotkey and command-line controls via subscription.
Setting up Monitorian is easy
Installing takes a couple of minutes
Now that you are impressed with Monitorian and want it asap for your setup, you will be glad to know that it takes a few minutes to download and set it up. Here is what you need to do:
- Launch Microsoft Store or head over to the Monitorian Microsoft Store page.
- Download and install the tool on your PC.
- Launch it once the download finishes, and it will automatically scan for every DDC/CI capable display connected to the PC.
- Right-click the tray icon and check the “Start on sign-in” option if you want to run it every time your PC boots up.
It may not always work well, though. Sometimes a display just won’t appear in the list, and it’s rarely Monitorian’s fault. If we go over to the apps’ own GitHub documentation, the usual culprits are a monitor that doesn’t support DDC/CI at all, a DDC/CI toggle sitting switched off in the monitor’s on-screen menu, or a docking station/adapter in between that does not pass DDC/CI signals through.
In such a case, you should check your monitor’s on-screen display for a setting labeled DDC/CI, DDC, or similar, and turn it on. If you are going through a dock, try connecting straight to your PC’s DisplayPort or HDMI port to rule that out. And if the built-in slider on your laptop itself has gone missing too, that’s usually a driver problem, and you should apply some handy troubleshooting fixes.
There are paid add-ons that are optional, not necessary
Twinkle Tray is another option you can try
While Monitorian is a good way to adjust the brightness for multiple displays, another app called Twinkle Tray is also recommended quite often. You can give it a try, and honestly, the two apps solve the same problem in slightly different ways. Twinkle Tray’s flyout menu looks closer to the Windows Quick Settings panel plus gives you built-in volume and power controls.
Monitorian, on the other hand, feels simpler, has a smaller footprint, and a settings screen that gets out of your way. There are other multi-monitor brightness tools that you can try your hand at. Monitorian is completely free for brightness and contrast controls. You can also subscribe, which unlocks hotkeys, command-line control, and support for more than four monitors at once. Overall, Monitorian is an easy choice if you want a simple solution for controlling brightness.