You can use an external display or projector with a Mac notebook while its built-in display is closed. This is known as closed-clamshell or closed-display mode.
To use closed-display mode with your Mac notebook, here's what you need:
- An AC power adaptor or an external display that provides power over USB-C or Thunderbolt 3 (USB-C).
- An external keyboard and mouse or trackpad, either USB or wireless.
- A USB-C to USB adaptor or cable if you're using a USB mouse or keyboard with a Mac that has USB-C ports.
- An external display or projector.
Enable closed-display mode
- Connect your USB keyboard or mouse to your Mac or external display, or pair your Bluetooth keyboard or mouse with your Mac. If you use a Bluetooth keyboard or mouse, choose Apple () menu > System Preferences, click Bluetooth, then verify Bluetooth is on.
- Connect your Mac to power with the AC power adaptor. Some external displays, like the LG UltraFine 5K, also charge your Mac.
- Connect your external display or projector to the appropriate port on your Mac. Use an Apple video adaptor if necessary. Some external displays have a USB cable that needs to be connected to your Mac.
- After your Mac notebook's desktop appears on the external display, close your computer's lid. You might have to press a key or click your mouse to wake the external display.
If your external display or projector doesn't turn on after you connect it to your Mac, connect your display while your Mac is asleep or off, then wake or turn on your Mac.
Disconnect your display or projector
Before you disconnect your display or projector, put your Mac to sleep.
Choose Apple () menu > Sleep, then disconnect your display or projector.