Whether you’re planning to sell your MacBook Air and want to erase its data for security reasons, or you want to start from scratch with a fresh install of macOS, follow this tutorial to wipe all data from your computer.

You can choose to restore your MacBook to factory settings, which will erase all of your personal data, or completely wipe the computer’s disk without installing an operating system. This is rarely the best choice.

Before you begin erasing your MacBook Air, back up all of the data on the machine so that you have a duplicate. Any data left on the laptop when you erase it will be permanently lost. Follow these steps to back up your MacBook to an external storage device using Time Machine, which is installed on your Mac:

Connect an external storage device to the port on your MacBook Air.