Audio
What is a CAF file?
Updated Jul 2026
CAF (Core Audio Format) is an Apple audio container built to hold lossless sound without the size limits older formats ran into. It shows up in iPhone voice memos, macOS system sounds, and Logic Pro or GarageBand projects. Its main limitation is that almost nothing outside Apple's own software opens it directly.
- Extension
- .caf
- Type
- Audio
- Typically
- Apple audio
Why CAF exists
Apple introduced CAF with Mac OS X Tiger in 2005 as a replacement for AIFF and WAV, both of which cap out at 4GB and struggle with very long or high-resolution recordings. CAF has no such ceiling, so it became the format Apple's own tools reach for internally.
As a container, CAF doesn't lock you into one codec. It can hold plain uncompressed PCM audio or Apple Lossless (ALAC), plus extra data like channel layout, markers, and text tied to specific points in the recording. That flexibility is why apps like Logic Pro, GarageBand, and even the iPhone's Voice Memos and text-to-speech engine store audio this way.
The trouble is compatibility. A CAF file plays fine in Apple's own apps, but hand it to a Windows PC, a random media player, or most editing software and it just won't open. People usually meet CAF when they export a voice memo, pull audio out of a GarageBand project, or copy a system sound file, then find they need a WAV or MP3 before they can actually use it anywhere else.
The trade-offs
Strengths
- Fully lossless, no quality lost compared to the original recording
- No practical file size limit, unlike older AIFF or WAV files
- Can carry extra data like markers and channel layout alongside the audio
Watch-outs
- Barely supported outside Apple's own apps and operating systems
- Most editing software and media players can't open it directly
- Usually needs converting to WAV or MP3 before you can share or edit it
A note on privacy
A CAF file doesn't typically carry location data the way a photo does, but it often is the recording itself, a voice memo, a dictated note, or a personal audio clip someone wants to convert to share. Running that through an online converter means uploading the actual sound of your voice to a server you don't control. Converting it on your own computer keeps the recording, and whatever's said in it, on your machine the whole time.
Questions
How do I open a CAF file?
Apple's own apps, like QuickTime Player, Logic Pro, and GarageBand, open CAF files without any extra steps. On Windows or in most other software, you'll usually need to convert it to WAV or MP3 first.
Is CAF better than WAV?
CAF removes WAV's 4GB size limit and can pack in extra data like markers, which matters for long recordings or production work. For everyday listening and sharing, WAV is more widely supported, so CAF's advantages mostly matter inside Apple's own tools.
Why does my iPhone save audio as CAF?
iOS uses CAF internally for things like Voice Memos and system sounds because it handles long recordings and extra metadata cleanly. It's a storage choice Apple makes for you, not something you select.
Can I convert a CAF file without uploading it?
Yes. A desktop app like Morphjet converts CAF files on your own computer, so the recording never leaves your device.
Is CAF the same as ALAC?
No. CAF is a container, ALAC is a codec that can live inside it. A CAF file might hold Apple Lossless audio, or it might hold plain uncompressed PCM instead.
Morphjet opens and converts CAF and 1,800+ other formats, all on your own computer. Launching this July.