Free online AAC to CAFF converter

Source format: AAC

AAC (Advanced Audio Coding) is a compressed audio format designed to deliver better sound quality than MP3 at similar bitrates. It is widely used by Apple devices and software, streaming platforms, mobile phones, and media players. AAC files are common for music, podcasts, and other audio content where efficient compression and broad playback support matter.

Target format: CAFF

CAFF (Core Audio Format) is an audio container developed by Apple for storing uncompressed or compressed audio, metadata, and channel information. It is mainly used in macOS and professional audio workflows. CAFF is useful when you need a flexible Apple-native format for editing, archiving, or exchanging audio with software that supports Core Audio formats.

How to perform the conversion

The most practical way to convert .aac to .caff is with FFmpeg, a reliable command-line tool that supports both formats. If you prefer a graphical workflow, you can also use Audacity or compatible macOS audio tools, but support for exporting directly to CAFF may vary. You can convert the file on 101convert.com for free, without installing any software.

1. Install FFmpeg if it is not already available on your system.
2. Open a terminal or command prompt.
3. Run a command such as ffmpeg -i input.aac output.caff.
4. Check the resulting file in a player or editor that supports CAFF.

If the source AAC file is inside an MP4/M4A container rather than a raw AAC stream, FFmpeg will still usually detect it correctly. If needed, you can first inspect the file with ffprobe input.aac to confirm the audio stream details.

Quality, compatibility, and limitations

AAC is already compressed, so converting it to CAFF does not improve audio quality. If the CAFF output is encoded as uncompressed PCM, the file may become much larger. If it is re-encoded to another compressed codec inside CAFF, quality may remain similar but can still suffer from additional generation loss if the audio is decoded and encoded again.

Compatibility is the main limitation: CAFF is much less universally supported than AAC. Many players and web services can open AAC, while CAFF is mostly useful in Apple-centric or professional audio environments. For best results, keep the original AAC file if you need broad playback compatibility, and use CAFF only when a specific application or workflow requires it.