How to Encrypt an External Drive on macOS

Step by step

1. 1 min

   Back up existing data

   Encryption requires reformatting the drive, which will erase all existing files. Copy all data currently on the drive to a secure secondary location before proceeding.

   Note: Encryption cannot be applied to an existing volume without clearing its contents.
2. 30 sec

   Open Disk Utility

   Press Command + Space to open Spotlight Search. Type 'Disk Utility' and press Return to launch the application.

   Note: Cmd + Space
3. 30 sec

   Locate the external drive

   Click the View button in the top-left toolbar and select 'Show All Devices.' Select the root level of your external drive in the sidebar to ensure you are formatting the entire disk.

4. 30 sec

   Initiate the erase process

   Click the Erase button in the toolbar. A dialog box will appear requiring you to define the volume properties.

5. 1 min

   Set encryption parameters

   Enter a name for your drive, select 'GUID Partition Map' as the Scheme, and choose 'APFS (Encrypted)' as the format. You will be prompted to enter and verify a strong password; do not lose this, as there is no password recovery option for encrypted volumes.

   Note: Use the key icon to generate a random high-entropy password if needed.
6. 1 min

   Finalize encryption

   Click Erase. macOS will partition the drive, apply the encryption keys, and mount the volume. Once the progress bar finishes, click Done.

   Note: The drive will now prompt for your password whenever it is connected to a Mac.