Disk Utility User Guide

Disk Utility is a system utility for performing disk and disk volume-related tasks on macOS and Mac OS X systems. With this easy-to-use program, you can perform tasks as the following: Mount, unmount, and eject connected hard drives including SSDs. Partition schemes available in Disk Utility on Mac. Get detailed information about a disk. Manage physical disks and volumes. Add, erase, or delete APFS volumes. Erase and reformat a storage device. Encrypt and protect a storage device with a password. Partition a physical disk.

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.

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.

Give your disk a checkup

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

To explore the Disk Utility User Guide, click Table of Contents at the top of the page, or enter a word or phrase in the search field.

These steps apply only to Mac computers with an Intel processor. The steps to erase a Mac with Apple silicon are different.

Before erasing your Mac

Make a backup of any files that you want to keep. Erasing your Mac permanently deletes its files.
If you want to restore your Mac to factory settings, such as to prepare it for a new owner, first learn what to do before you sell, give away, or trade in your Mac. Then erase your Mac as the final step.

Use Disk Utility to erase your Mac

Start up from macOS Recovery: Turn on your Mac, then immediately press and hold these two keys until you see an Apple logo or other image: Command (⌘) and R.
If asked, select a user you know the password for, then enter their administrator password.
From the utilities window, select Disk Utility and click Continue.
Select Macintosh HD in the sidebar of Disk Utility. Don't see Macintosh HD?
Click the Erase button in the toolbar, then enter the requested details:
- Name: Macintosh HD
- Format: APFS or Mac OS Extended (Journaled), as recommended by Disk Utility
Click Erase Volume Group. If you don't see this button, click Erase instead.
If asked, enter your Apple ID. Forgot your Apple ID?
After the erase is done, select any other internal volumes in the sidebar, then click the delete volume (–) button in the toolbar to delete that volume.
Disregard any internal volume named Macintosh HD or Macintosh HD - Data, as well as any volumes in the External and Disk Images sections of the sidebar.
Quit Disk Utility to return to the utilities window.
If you want to start up again from the disk you erased, select Reinstall macOS in the utilities window, then click Continue and follow the onscreen instructions to reinstall macOS.

Disk Utility Mac Os X

If you don’t see Macintosh HD in Disk Utility

Your built-in startup disk should be the first item listed in the Disk Utility sidebar. It's named Macintosh HD, unless you changed its name. If you don't see it there, choose Apple menu  > Shut Down, then unplug all nonessential devices from your Mac and try again.

Disk Utility Macbook Pro

If your disk still doesn't appear in Disk Utility, or Disk Utility reports that the erase process failed, your Mac might need service. If you need help, please contact Apple Support.

Disk Utility Mac Apfs

Learn more

Disk Utility Mac Pro

For more information about using Disk Utility, see the Disk Utility User Guide.