APFS, exFAT or Mac OS Extended: which format to use

Which format should I choose?

A format, or file system, is the way a drive organizes its files. Apple’s current Disk Utility guide lists APFS, ExFAT and MS-DOS (FAT); Mac OS Extended appears in its guides for macOS Sequoia and earlier:

Apple lists only ExFAT and MS-DOS (FAT) as compatible with Windows. Time Machine can’t back up to a disk formatted for Windows.

Is APFS or exFAT better for an external SSD?

APFS, if the SSD only connects to Macs. Apple says APFS is optimized for the flash storage in SSDs, and brings strong encryption, space sharing, snapshots and fast directory sizing. Choose ExFAT only when the SSD also has to work with a Windows PC: it’s the Windows format Apple suggests for drives over 32 GB. An ExFAT drive can’t hold your Mac’s Time Machine backups.

APFS comes in four versions. Plain APFS is the one to choose unless you need the others:

• APFS (Encrypted) uses APFS and encrypts the volume.
• APFS (Case-sensitive) treats file and folder names that differ only in capital letters, such as “Homework” and “HOMEWORK”, as different.
• APFS (Case-sensitive, Encrypted) does both.

APFS or Mac OS Extended for a hard drive?

APFS works on hard drives too. Apple says it’s optimized for SSDs but can also be used with traditional hard disk drives and external, direct-attached storage. Mac OS Extended (Journaled) is the file system of macOS 10.12 and earlier. Apple’s current Disk Utility guide no longer lists it, so on a current Mac choose APFS, unless the drive must also work with a Mac that old and your Disk Utility still offers it.

A Time Machine disk that’s already Mac OS Extended can stay as it is. Time Machine still supports backups on Mac OS Extended (Journaled) disks, and it doesn’t ask you to erase one that already holds a backup. A new backup disk that isn’t APFS gets the option to erase and reformat it.

How do I check what format a drive uses?

1. Open Disk Utility. It’s in Applications > Utilities, or search for it with Spotlight.
2. Choose View > Show All Devices.
3. Select the drive’s volume in the sidebar, then click Info in the toolbar.

The Info window shows whether the drive is internal or external, the format in use, its total capacity, the space available and where it’s mounted.

How do I format an external drive on a Mac?

Erasing a drive deletes everything on it. Copy any files you want to keep to another drive first.

1. Open Disk Utility and choose View > Show All Devices.
2. In the sidebar, select the drive itself, at the top of its list, then click Erase.
3. Click the Scheme pop-up menu and choose GUID Partition Map. If there’s no Scheme menu, you’ve selected a volume instead of the drive.
4. Click the Format pop-up menu and choose a format: APFS for Macs, or ExFAT to share with Windows.
5. Enter a name, click Erase, then click Done.

There’s a shortcut in the Finder too: Control-click the drive in the sidebar, choose Erase Disk, enter a name, choose a format and click Erase.

Questions people also ask

Can a Mac use an exFAT drive?

Yes. Disk Utility formats drives as ExFAT, and Apple suggests it for drives over 32 GB that you use with both a Windows computer and a Mac.

Can I change a drive’s format without erasing it?

Not in Disk Utility: you choose the format when you erase the drive, and erasing deletes everything on it. Copy your files off first, then copy them back.

Should I choose APFS (Encrypted)?

Choose it when the drive holds private files. It uses APFS and encrypts the volume.

Can Time Machine back up to an exFAT drive?

No. Time Machine can’t back up to a disk formatted for Windows. Apple’s preferred format for a backup disk is APFS or APFS (Encrypted).