Windows 10 offers multiple options and settings to change the default settings of the second monitor. For instance, you can change the second monitor resolution with ease. However, there is no option to change the screen brightness of the second or third monitor connected to your laptop.
If you are on a multi-monitor setup, you might want to have an option to change the brightness of your second monitor right from within Windows 10 instead of using the physical buttons on the external monitor.
While Windows 10 doesn’t offer an option to adjust the screen brightness of the second monitor, there is a cool app out there to help you adjust the external monitor brightness right from the Windows 10 taskbar.
Monitorian: Adjust external monitor brightness in Windows 10
Monitorian is a free app available for Windows 10 to adjust the external monitor brightness right from the Windows 10 taskbar area. The free version of the Monitorian supports up to a maximum of 4 monitors, which should be good enough for most users.
After installing the software, click on its icon in the system tray to see the built-in as well as external displays connected to your computer. Drag the slider to adjust the screen brightness. The flyout displays the actual name and model of external monitors to avoid confusion while using two or more external monitors.
Besides that, the Monitorian software also enables you to simultaneously adjust the screen brightness of all displays (built-in as well as external monitor/s). To do that, right-click on the Monitorian app icon in the system tray and then select Enable moving in unison option.
The Monitorian software is also available in the classic desktop version in addition to the app available in the Windows 10 Store. The desktop version is suitable for easier versions of the Windows operating system (works great on Windows 10 as well).
The app supports all monitors that are DDC/CI compatible. Most of the monitors out there to support DDC/CI. If the app is not recognizing your external monitor, please make sure that DDC/CI is enabled on the monitor (use the physical buttons on the monitor to access the setting).
As said earlier, the free version of the app supports up to four monitors. Get it from the below link.
Download Monitorian (desktop version)