Note: Modern versions of macOS will prompt you to use FileVault 2 to encrypt your entire drive. We highly recommend you take this step to protect your data. If you encrypt your entire drive, you don’t have to worry much about doing secure deletion since the master encryption key is protected with a password that you control, and that you can change or erase to make data on the drive irretrievable. More information is available on encrypting with FileVault 2. The instructions below should only be used for securely deleting data from spinning drives.