Four volumes in the APFS container in the Disk Utility sidebar.

Let macOS manage space between multiple volumes

With Apple File System (APFS), the file system introduced in macOS 10.13, you can easily add and delete volumes on your storage devices. APFS-formatted volumes automatically grow and shrink — you never have to repartition a storage device again.

How to add a volume to an APFS container

The APFS (Encrypted) option in the Format menu.

Keep your external storage devices secure

When you get a new flash drive or other storage device, format it as APFS and encrypt it with a password to protect its contents.

How to protect a storage device with a password

The First Aid dialogue in the Disk Utility toolbar.

Give your disk a check-up

If you’re having problems with a disk, Disk Utility can check the disk and repair problems it detects.

How to repair a disk

To browse the Disk Utility User Guide, click Table of Contents at the top of the page.