How to Clean Install macOS on an Apple Silicon M1 Mac

Erasing your iPhone or iPad completely is dead simple (Settings app > General > Reset > Erase All Content and Settings). But not so much on Mac. Intel Macs required a particular series of steps that were not obvious. That's also true with the new Apple Silicon M1 Macs, though it's an entirely different set of non-obvious steps.

I wish I had screenshots to share but I haven't had my hands on one of these new computers just yet. I've only helped people with this over the phone. I'll update this article with helpful screenshots when I am able to.

Before you start

• Copy everything off that you want to keep. This will erase everything from your computer and there is absolutely no way to undo this.
• Unplug any devices from the computer that you don't absolutely need. You don't want to accidentally erase your backup drive.
• Make sure that your computer is fully updated if you can. Go to the Apple menu > System Preferences > Software Update.

Boot into Recovery mode

1. Turn the computer completely off
2. Press and hold the power button until you see icons. If you are using a MacBook that's the unlabeled button in the upper right corner of your keyboard.
3. Click the Options icon and then click Continue.
4. You may be prompted to connect to your WiFi network, log in with an account from the computer, and/or choose your language. Go ahead and do that.

Erase the Mac

1. Click the "Utilities" menu on top of your screen and choose "Terminal"
2. This opens a window like you see in the movies or on old computers where you type commands on the keyboard. Type resetpassword followed by the return key.
3. Click on the new window that appears to bring it to the foreground
4. Click the Recovery Assistant menu on top of the screen
5. Click “Erase Mac…” and follow the prompts to erase your Mac
6. Wait for the computer to restart, and if prompted log in with your iCloud account to remove the activation. No one else will be able to log into the computer until you do this.

Reinstall macOS

1. Click "Reinstall macOS"
2. Follow the prompts, wait for the install which could take 30 minutes to several hours depending on your internet speed.

If at this point you are intending to have someone else set up the computer, you can press Command-Q to turn it off and let them set it up later.

Photo by Kim Gorga on Unsplash