DisplayDisabler — Lightweight Display Manager for macOS

A minimal, open-source menu bar app that disables your MacBook's built-in display when using external monitors. Uses the same private CoreGraphics API as BetterDisplay, in a ~100KB app with zero background overhead.

Install

make

Then drag DisplayDisabler.app to /Applications. That's it.

Or use the shortcut:

make install

What It Does

Click the display icon in your menu bar to:

• See all displays — names, status, resolution, refresh rate, HiDPI info
• Disable / Enable any display with one click
• Browse all resolutions — including every HiDPI (Retina) mode
• Force HiDPI on non-Retina displays via virtual display mirroring (macOS 14+)
• Auto-disable built-in when an external monitor is connected
• Launch at Login — starts silently in the menu bar

No dock icon. No terminal. No scripts. Just a clean menu bar utility.

Menu Bar

DisplayDisabler v3.0
1 online, 1 active
─────────────────────────────────────────────
● Built-in Display — 0x1
  active  │  built-in  │  main
  3024 × 1964 @2x  120Hz
  ▶ All Resolutions              → submenu
  Force HiDPI                      (if no native HiDPI, macOS 14+)
  Disable This Display
─────────────────────────────────────────────
▶ Settings
  ├── ☐ Turn off laptop screen when external monitor is connected
  ├── ☑ Show notifications
  ├── ☐ Ask before disabling a display
  ├── ☑ Show all resolutions
  └── ☐ Launch at Login
─────────────────────────────────────────────
Quit DisplayDisabler                      ⌘Q

The All Resolutions submenu shows every available display mode — HiDPI and standard — with pixel dimensions, logical dimensions, scale factor, and refresh rate. All settings are toggleable and persist across app restarts.

Build from Source

Requires Xcode Command Line Tools (xcode-select --install).

make            # build DisplayDisabler.app
make install    # copy to /Applications
make clean      # remove build artifacts
make uninstall  # remove from /Applications

Compilation details

clang -fobjc-arc -Wall -O2 -mmacosx-version-min=13.0 \
      -framework Cocoa -framework CoreGraphics -framework IOKit \
      -framework ServiceManagement -framework UserNotifications \
      main.m AppDelegate.m DisplayManager.m -o DisplayDisabler

How It Works

The core functionality uses Apple's private CoreGraphics API:

CGBeginDisplayConfiguration(&config);
CGSConfigureDisplayEnabled(config, displayID, false);  // private API
CGCompleteDisplayConfiguration(config, kCGConfigurePermanently);

This is exactly what BetterDisplay does internally.

Force HiDPI works by creating a CGVirtualDisplay (private API, macOS 14+) with HiDPI enabled, then mirroring the physical display through it via CGConfigureDisplayMirrorOfDisplay.

The app monitors display changes via CGDisplayRegisterReconfigurationCallback and NSApplicationDidChangeScreenParametersNotification, and auto-refreshes the menu when you plug/unplug monitors.

vs BetterDisplay

	DisplayDisabler	BetterDisplay
App size	~100KB	~30MB
Memory	~5MB	~120MB
Background CPU	0%	~0.5%
Open source	Yes	No
HiDPI mode listing	Yes	Yes
Force HiDPI	Yes (macOS 14+)	Yes
Auto-disable built-in	Yes	Yes
Launch at Login	Yes	Yes
HDR / DDC control	No	Yes
GUI settings	Menu bar	Full GUI

Requirements

• macOS 13+ (Ventura or later)
• Apple Silicon or Intel Mac

Files

File	Purpose
main.m	App entry point
AppDelegate.h/m	Menu bar UI, settings, auto-disable logic
DisplayManager.h/m	Display query, enable/disable, mode listing, HiDPI forcing, monitoring
Info.plist	App bundle metadata
Makefile	Build system

Security

• Uses official (though private) Apple APIs
• No network access, no data collection
• Source code fully auditable
• Does NOT require SIP disabled or root access
• Ad-hoc code signed (works locally, not notarized for distribution)

License

MIT License — see LICENSE

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Version: 3.0.0 Compatible with: macOS 13+ (Ventura and later), Apple Silicon & Intel