Mac storage basics · Disks, APFS and formats

What is APFS?

Q: What is APFS?

APFS (Apple File System) is the format macOS uses for its startup disk and recommends for SSDs. It's designed for flash storage and brings features older Mac formats lacked: instant file copies (clones), snapshots, space sharing between volumes, and built-in encryption. Every Mac running a recent macOS uses APFS for its internal drive. External drives can use APFS too, which is the best choice when the drive is only used with Macs running macOS 10.13 or later.

Short answer: Apple File System, the format macOS uses for its startup disk and recommends for SSDs. It adds clones, snapshots, space sharing between volumes and built-in encryption.

APFS (Apple File System) is the format macOS uses for its startup disk and recommends for SSDs. It's designed for flash storage and brings features older Mac formats lacked: instant file copies (clones), snapshots, space sharing between volumes, and built-in encryption.

Every Mac running a recent macOS uses APFS for its internal drive. External drives can use APFS too, which is the best choice when the drive is only used with Macs running macOS 10.13 or later.

Last reviewed October 1, 2026

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What is APFS?

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