Clamshell mode: using a MacBook closed with one monitor

Clamshell mode runs a MacBook with its lid closed and an external display as the only screen. It needs power connected, a display, and a keyboard and pointer (wired or Bluetooth). Close the lid and the external display carries on alone.

Setting it up

1. Connect the power adapter and the external display.
2. Connect or pair a keyboard and a mouse or trackpad.
3. Close the lid. The display may go dark for a moment, then come back as the only screen.

Recent Apple silicon MacBooks can also stay awake on battery with the lid closed when an external display is connected. If yours sleeps, plug in power.

Why windows jump around

Closing or opening the lid adds or removes a display. macOS moves every window that was on the display that went away, and it does not always move them back. That is why windows end up stacked on one screen after you open the lid again.

• Close the lid before you unplug the display, and open it after plugging in, so fewer windows have to move.
• In System Settings, Desktop & Dock, Displays have separate Spaces decides whether each screen keeps its own desktops.
• See windows moving after unplugging a monitor for more fixes.

Keeping your layout

ClutterFreeMac keeps a strip of windows on each display. When a display comes or goes, it checks the strips against what is open, and nothing is left parked off screen. On one big external display in clamshell mode, the strip is at its best: more columns fit, and the rest stay one swipe away.