!! I would recommend using xanderfrangos/twinkle-tray instead which now provides a much better implementation of this functionality as of v1.17.
A lightweight background utility for Windows 11 that provides laptop-style hotkeys with OSD to adjust "SDR content brightness" on HDR-enabled displays
Go to the Releases page
Download the latest SDRbright.exe and run it. The application can be accessed from the system tray.
Ctrl+Win+= Increase brightness by 10
Ctrl+Win+- Decrease brightness by 10
The official SDR Brightness slider in Windows configures the SDR white level through a direct undocumented interface with the graphics driver and d3d12. Because there are no publicly available APIs for this purpose, this program has to use a workaround. To adjust brightness, an instance of SystemSettings.exe is created in the background, and a UIAutomation interfaces with the brightness slider. The process is kept alive for 5 seconds after adjustment in case another is needed.
This is a very roundabout way of doing things, and any Windows update could break it, but it's the most reliable and only working method unless Microsoft can improve how poorly HDR is implemented in Windows right now.
Note that Windows' HDR mode should should only be permanently enabled for displays capable of per-pixel brightness control (OLED or Mini-LED), as with traditional backlit or non-HDR-compliant displays SDR content (inc. the desktop) will look washed out and clipping will occur in bright and dark areas.
x64 Windows 11
.NET 8.0 Runtime
Use Visual Studio 2026 with the .NET 8.0 SDK
This project is licensed under the GNU GPLv3 License. Icons adapted from microsoft/fluentui-system-icons