What is the “Start Up Automatically” Setting?
Deep within the macOS system settings is a feature designed primarily for desktop Macs (like the Mac mini, Mac Studio, and iMac) called “Start up automatically after a power failure.” When enabled, if your Mac loses power due to a blackout or a disconnected cable, it will instantly boot itself back up the moment electricity is restored.
While useful for servers that need to stay online, this feature can be dangerous for home users. If your area experiences rolling blackouts with power flickering on and off rapidly, your Mac will repeatedly attempt to boot and abruptly die, which can severely corrupt your file system.
How to Disable Automatic Startup After Power Failure on Mac
You can easily disable this setting to protect your Mac’s internal drive during power fluctuations.
- Click the Apple Logo in the top-left corner of the screen.
- Select System Settings… from the dropdown menu (or System Preferences on older macOS versions).
- If you are using macOS Ventura or later, click on Displays in the left sidebar, then click the Advanced… button at the bottom. (On macOS Monterey or earlier, click on Energy Saver).
- Look for the checkbox labelled Start up automatically after a power failure.
- Uncheck the box to disable the feature.
- Click Done (if applicable) and close the Settings window.
Now, if the power goes out, your Mac will remain safely powered off when the electricity returns, allowing you to manually turn it on once the power grid is stable.