Lunar is a macOS app for controlling external monitors through intelligent adaptive brightness and hardware controls.
The tool addresses the limitation that external monitors lack the adaptive brightness capabilities built into modern MacBooks and iMacs. Lunar communicates directly with monitors via the DDC/CI protocol to adjust hardware brightness, contrast, and volume rather than relying on software overlays. It offers multiple adaptive brightness modes: sensor-based adjustment using an external light sensor, sync-based adjustment using the MacBook or iMac's built-in light sensor, and location-based adjustment derived from sunrise and sunset times. The app also provides manual control through native keyboard hotkeys, input switching between monitor sources, screen orientation changes, and a BlackOut feature that powers down monitors while preserving USB-C charging, audio, and USB hub functionality.
Lunar suits anyone using external monitors with a MacBook or iMac who wants brightness to adjust automatically to ambient conditions or time of day. It works alongside macOS's native adaptive brightness for built-in displays and is compatible with Night Shift, True Tone, and similar tools. The tool supports XDR and HDR displays capable of 1000 to 1600 nits of brightness, and includes a sub-zero dimming mode for low-light work. Users can create app-specific presets to apply different brightness levels for particular activities like movie watching or design work.
The project maintains active development with regular updates addressing both new features and bug fixes. The codebase shows consistent refinement of the DDC protocol implementation and monitor compatibility. Development activity demonstrates responsiveness to user-reported issues and incorporation of feedback into subsequent releases. The tool receives ongoing optimization for both Intel and Apple Silicon architectures.
