APFS (Apple File System) is the file system that manages how data is stored and organised on Apple devices. It replaced HFS+ (Mac OS Extended) starting with macOS Sierra in 2017 and is now the default on all modern Apple hardware including Macs, iPhones, and iPads.
The main advantages of APFS over its predecessor include:
- Speed and efficiency. APFS reads and writes files faster and uses storage space more intelligently, reducing wasted disk capacity.
- Encryption. Built-in per-file encryption protects sensitive data at the file level, not just the volume level.
- Snapshots. APFS can create instant point-in-time copies of your entire system, useful for Time Machine backups and system recovery.
- Reliability. Crash-safe design ensures data integrity even if power fails during a write operation.
- Copy-on-write. Files are copied more efficiently because APFS only duplicates data that actually changes, not entire files.
When buying used or refurbished Apple devices, check that the storage uses APFS rather than the older HFS+ format. Older Macs may still run HFS+, which can cause compatibility issues with newer software and may perform noticeably slower.
If you're upgrading an older Mac and want to switch to APFS, you'll need to erase the drive and reinstall macOS. Apple provides migration tools to transfer your files safely during this process. Note that APFS works best with solid-state drives (SSDs) rather than traditional hard disk drives (HDDs), though it can function on both.