How to use only an external monitor on a MacBook

Published September 25, 2026 · by fanckush, who made SoloDisplay, one of the apps below

On Windows, Win+P > Second screen only turns the laptop screen off and leaves you with the monitor. macOS has no equivalent. These are the workarounds and what each one costs you.

1. Clamshell mode (lid closed)

This is Apple's built-in answer. Connect the monitor, connect power, use an external keyboard and mouse or trackpad, then close the lid. The Mac keeps running and only uses the monitor. Without power, closing the lid puts the Mac to sleep.

With the lid closed you lose:

• The built-in keyboard and trackpad.
• Touch ID, unless your keyboard has it.
• The camera and microphone.

If you have a full desk setup and never touch the laptop, clamshell mode is fine and needs nothing installed.

A known hack is to put a magnet over the lid sensor, so macOS thinks the lid is closed while it's actually open. The laptop screen turns off, but as far as macOS knows it's in clamshell mode, so it needs power the same way. The sensor's position differs between models, and a magnet resting on the laptop can scratch the screen when you close the lid.

2. Turning the brightness all the way down

With the lid open, hold the brightness down key until the screen goes dark. The screen looks off, but macOS still treats it as a display:

• Windows can still open on it.
• The pointer still crosses onto it when you go past the edge of the monitor.

In System Settings > Displays, drag the menu bar onto the monitor to make it the main display. New windows and the Dock then default to the monitor, but windows can still end up on the laptop screen.

3. Mirroring the displays

In System Settings > Displays you can mirror the laptop screen to the monitor, then dim the laptop. Now there's only one desktop, so nothing gets lost.

Set Optimize for to the monitor and it keeps its full resolution, while the laptop shows a scaled copy. The laptop screen stays on and shows everything on your monitor, just dimmed.

4. An app that turns the built-in display off

This is the macOS version of Second screen only: the laptop screen is actually off, macOS stops using it, and the keyboard, trackpad, Touch ID, camera and microphone keep working. macOS has no setting for it, but apps can do it. These are the ones I know of.

BetterDisplay

BetterDisplay is a full display management app covering resolution, HiDPI scaling, brightness, color and arrangement. On Apple silicon, one of its options disconnects the built-in screen automatically when an external display is connected. This is a Pro feature: BetterDisplay has a free version, but auto-disconnect needs the paid Pro license. It isn't open source. If you want more control over your displays than just this, it's the one to look at.

InternalDisplayOff

InternalDisplayOff is a small open source menu bar app. You can toggle the laptop screen from the menu bar or with Ctrl+Cmd+D, or turn on Auto Mode so it goes off when a monitor connects and comes back when the last one is unplugged. It turns the screen back on when it quits, lets the brightness keys control your monitor, and can switch external displays on and off too. It won't turn the screen off without an external display connected. You build it yourself with Xcode's command line tools, and it needs macOS Ventura or later. SoloDisplay started from the technique it uses.

displayplacer

displayplacer is a command line tool for setting resolution, arrangement and mirroring from Terminal, and it can also disable a screen with enabled:false. It's good for scripting a setup. It doesn't react when you plug or unplug a monitor, and its README warns that you may need to unplug and replug a disabled screen to get it back, which you can't do with a built-in one.

SoloDisplay

SoloDisplay is my app. It's a free, open source menu bar app that only does this job, automatically. You choose External Only once, and from then on the laptop screen turns off whenever a monitor is connected and comes back when you unplug. If the app quits or crashes, a helper process turns the screen back on. It also lets the Mac's brightness keys control your monitor's brightness, and, as an experiment, it can give you the laptop screen back when the monitor is switched to another input. It needs an Apple silicon MacBook on macOS Tahoe 26 or later.

Side by side

If you want the monitor alone and still use the MacBook's keyboard and Touch ID, pick an app: BetterDisplay for a full display toolkit, InternalDisplayOff if you don't mind building from source, displayplacer for scripts, or SoloDisplay for a ready-to-install app that does only this.