How to Set Up Automatic Restart of your Mac After an Unexpected Shutdown

This article explains how you can set your Mac to restart automatically after a power outage.

A lot of things (weather conditions, wild animals, human errors, equipment failure, etc) can cause a power outage. When this occurs, your Mac will be forced to shut down unexpectedly. Unless you turn on your Mac by pressing the power button, your computer will remain powered off. And this can be bad for you, for example, because you may work remotely and need to access your Mac remotely.

There is a way. In fact there are two ways to do this:

• Use Terminal
• Use Energy Saver

Terminal

You can use Terminal to set your Mac to automatically turn on after a power outage. Terminal offers a lot of customizations. Here is how:

Open Terminal on your Mac (Applications/Utilities folder). Use one of these commands (enter the command and hit enter, enter your passcode if asked):

Please note that if the % sign is already pre-typed in the Terminal app, do not enter it. Otherwise, Terminal will give you error messages like “command not found” etc.

Check this see if automatic restart is enabled

Enter the following command to see if your Mac is set to restart after a power failure. The result will say on or off.

% sudo systemsetup -getrestartpowerfailure

Enable or disable Mac to restart after a power failure

If you want to enable this, enter this code and hit enter:

% sudo systemsetup -setrestartpowerfailure on

And, enter this to disable it:

% sudo systemsetup -setrestartpowerfailure off

Check to see how long Mac waits to restart after a power failure

You can set a time in seconds before the computer starts. You can see if this is set:

% sudo systemsetup -getWaitForStartupAfterPowerFailure

How to set how long Mac waits to restart after a power failure

You can set a time. This must be 0 (zero) or a multiple of 30 seconds, such as 60 etc:

% sudo systemsetup -setWaitForStartupAfterPowerFailure seconds

seconds is the number, for example:

% sudo systemsetup -setWaitForStartupAfterPowerFailure 30

Energy Saver

You can use Energy Saver to do this too. But, unlike the Terminal method explained above, this method does not offer a lot of customizations. Here is how:

Open System Preferences and click Energy Saver.

And then ensure that “Start up automatically after a power failure” is selected.

See also

• How to Log out of, Sleep, Shut Down, Restart Your Mac Using Keyboard Shortcuts
• Your Computer was Restarted Because of a Problem: How to Fix Kernel Panic on Mac
• How To Use Terminal On Your Mac
• How to Start Up an Apple Silicon Mac (M Chip) in macOS Recovery
• How to Permanently Display or Automatically Hide and Show Menu Bar on Mac