Retired Document Important: This document may not represent best practices for current development. For current information, see About Apple File System.

Introduction

Important This document may not represent best practices for current development. For current information, see About Apple File System.

Apple File System is a new, modern file system for iOS, macOS, tvOS, and watchOS. It is optimized for Flash/SSD storage and features strong encryption, copy-on-write metadata, space sharing, cloning for files and directories, snapshots, fast directory sizing, atomic safe-save primitives, and improved file system fundamentals.

APFS replaces HFS+ as the default file system for iOS 10.3 and later, and macOS High Sierra and later.

Prerequisites

To understand how your app interacts with the file system, read File System Programming Guide.