Automatic power-on a Mac when power is connected

Summary

macOS Tahoe 26.5 adds a new power option that turns a Mac on whenever power is connected, including from a fully shut-down state. On supported hardware this lets our remote power control boot a machine that was powered off (accidentaly), without a physical power-button press or a support ticket.

Previously, the only related option restarted a Mac after a power failure while it was running. It did not power on a Mac that had been shut down.

What changed

Old behaviour (just autorestart)

New behaviour (autorestart + autorestartatconnect)

Trigger

Power restored after an unexpected loss

Power connected in any situation

Starting state that boots

Only a Mac that was running when power dropped

Any state, including a clean shutdown

Boots a shut-down Mac on power connect

No

Yes

Recovers after a power failure

Yes

Yes

With autorestart, a Mac that a customer or a script had shut down stayed off when power was cycled. The physical button (or a scheduled boot) was the only way back on. autorestartatconnect powers the Mac on whenever it sees power, regardless of how it was turned off.

Requirements

The feature needs both a supported macOS version and supported hardware.

  • macOS Tahoe 26.5 or later

  • One of:

    • Mac mini introduced in 2024 or later

    • Mac Studio introduced in 2025 or later

    • iMac introduced in 2024 or later

Impact on remote reboot

Our remote reboot works by cutting and restoring power to the node. With this setting enabled:

  • A running or crashed Mac reboots as before.

  • A Mac that was cleanly shut down now boots on the next power connect.

If you rely on remote reboot to recover a machine you may have shut down yourself, enable this setting so the node comes back on its own.

Enable via System Settings

  1. Apple menu > System Settings.

  2. Select Energy in the sidebar.

  3. In Start up when power is connected, choose Always.

The option only appears on hardware and macOS versions that meet the requirements above.

Enable via Terminal

Changing this requires root, so use sudo.

Enable:

sudo pmset autorestartatconnect 1

Disable:

sudo pmset autorestartatconnect 0

Verify the current value:

pmset -g | grep -i autorestart

A value of autorestartatconnect 1 confirms the setting is active.

References