jakehilborn/displayplacer
Displayplacer
Displayplacer is a command-line tool for managing multi-monitor display layouts on macOS. It enables users to save, apply, and automate screen configurations including resolution, rotation, arrangement, and mirroring settings entirely from the terminal without requiring a graphical interface.
The tool identifies displays using persistent hardware IDs rather than port-based identifiers, allowing layouts to be restored consistently across reconnections and reboots. It supports headless display configuration, enabling or disabling monitors, rotating internal and external displays, and designating a primary screen. Mirroring setups are handled with automatic resolution optimization for the primary display in a mirrored group.
Displayplacer encodes full multi-monitor parameters into compact string arguments for easy saving and replaying of layouts. It can list current screen configurations as command-line arguments for creating reusable profiles, and applies only valid configurations by matching requested settings against supported hardware modes. The tool also provides session-aware identifier fallback for maintaining layout stability when macOS reassigns hardware IDs.