Dim any window on your Windows desktop — a quick privacy shield for when someone walks by.
Pick a window from the list, check it, and a semi-transparent dark layer covers it. Each window has its own slider, so you can dim each one to exactly the strength you want. The overlay is click-through: you can keep interacting with the window underneath.
- Per-window dimming — check the windows you want, tune each one independently with its own slider
- Click-through overlays — the dim layer never blocks your mouse or keyboard
- Follows the window — the overlay stays pinned to the window as you drag it, auto-hides when minimized, and disappears when the window closes
- Lightweight — pure Win32 layered windows, no bitmap trickery, near-zero CPU when idle
- No admin rights, no install — a single portable exe
The app is a small WinUI 3 UI that lists top-level windows. Dimming is done by native Win32 layered windows (black brush + SetLayeredWindowAttributes alpha), each created as an owned window of its target. Windows' own ownership rules then handle the hard parts for free: the overlay always stays above its target, hides with it, and dies with it.
All Win32 work runs on one dedicated background thread — no locks, just a message pump.
- Windows 10 1809+ (64-bit)
dotnet build WinWindowDimmer.csproj -p:Platform=x64Run the exe:
bin\x64\Debug\net8.0-windows10.0.19041.0\win-x64\WinWindowDimmer.exe
- Launch WinWindowDimmer
- Check the window you want to hide (hint: drag it into view first, then Refresh)
- Drag its slider to set how dark it gets
- Uncheck when you want it back
MIT