Dim background windows. Focus on the one that matters.
OpenHaze highlights your active window by fading everything behind it into an adjustable haze, from a soft shade to a total blackout. It is an open-source recreation of the excellent HazeOver for macOS, plus a native Windows sibling that HazeOver never had.
Both implementations are small, dependency-free, and native:
| macOS | Windows | |
|---|---|---|
| Code | Swift + AppKit, ~1,700 lines | C# + WinForms, ~1,400 lines |
| Builds with | plain Command Line Tools (swiftc) |
the csc.exe bundled inside Windows |
| Get started | macos/ |
windows/ |
- Dim all background windows; the front window stays bright
- Adjustable intensity (0 to 100%) with smooth crossfade transitions
- Highlight a single window or all windows of the front app
- Multi-monitor modes: independent focus per display, or one lit display with the rest fully dimmed
- Menu bar / tray slider, and scroll over the icon to adjust intensity
- Global hotkeys (toggle, intensity up/down)
- Custom haze color, desktop-click reveal, launch at login
- macOS extras: Fn-to-reveal gesture, separate Light/Dark appearance settings, AppleScript +
openhaze://URL scheme automation
Grab a build from the releases page, or build from source in seconds:
# macOS
cd macos && ./build.sh --install --run
# Windows: double-click windows\build.bat, or from a terminal:
cd windows && build.batAll settings live in the tray/menu-bar UI; nothing needs a config file edit.
| Setting | Where it is stored |
|---|---|
| Intensity, haze color, per-monitor mode, hotkeys, launch at login | macOS: standard defaults preferences. Windows: %APPDATA%\OpenHaze\settings.txt |
The trick is the same on both platforms: full-screen, click-through overlay windows are inserted into the global z-order directly beneath the focused window (NSWindow.order(.below, relativeTo:) on macOS, SetWindowPos(overlay, hWndInsertAfter: foreground, ...) on Windows). Everything below the overlay is hazed; the focused window and everything above it stays bright. Two overlays per display crossfade for smooth transitions. Focus changes come from Accessibility events (macOS) or SetWinEventHook (Windows), with a cheap window-list poll as a fallback and drift corrector.
Inspired by, and a tribute to, HazeOver by Pointum. This project reimplements the concept from scratch for personal use and shares no code or assets with the original. If you like the idea, buy HazeOver.
See CONTRIBUTING.md. Report vulnerabilities privately per SECURITY.md.