Apple Lossless Audio Codec
Writableaudio
Apple Lossless, also known as Apple Lossless Audio Codec (ALAC), or Apple Lossless Encoder (ALE), is an audio codec developed by Apple Inc. for lossless data compression of digital music. Apple Lossless data is stored within an MP4 container with the filename extension .m4a.
Identify it
| Extensions | .m4a.mp4.caf |
|---|---|
| Signatures | 667479704d344120 at byte 4 (Apple Lossless Audio Codec) |
| PRONOM | fmt/596 |
| Wikidata | Q621277 |
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Open it
- FFmpegOpen source
- mutagenOpen source
- PlexOpen source
- Q141674392Open source
Convert it
| To | With | Fidelity | Command and losses |
|---|---|---|---|
| FLAC (Free Lossless Audio Codec) 1.2.1 | FFmpeg | Lossless | ffmpeg -i in.caf out.flacLossless for decoded audio; a lossy source stays as degraded as it was. WAV may reduce bit depth or drop metadata. |
| Waveform Audio | FFmpeg | Lossless | ffmpeg -i in.caf out.wavLossless for decoded audio; a lossy source stays as degraded as it was. WAV may reduce bit depth or drop metadata. |
| Matroska 1-4 | FFmpeg | Lossy | ffmpeg -i in.caf out.mkvRe-encoded with lossy codecs by default; try `-c copy` to remux without re-encoding when the codecs fit the container. |
| MPEG 1/2 Audio Layer 3 | FFmpeg | Lossy | ffmpeg -i in.caf out.mp3Lossy re-encoding. |
| MPEG-4 Part 14 | FFmpeg | Lossy | ffmpeg -i in.caf out.mp4Re-encoded with lossy codecs by default; try `-c copy` to remux without re-encoding when the codecs fit the container. |
| Ogg | FFmpeg | Lossy | ffmpeg -i in.caf out.oggLossy re-encoding. |
| WebM | FFmpeg | Lossy | ffmpeg -i in.caf out.webmRe-encoded with lossy codecs by default; try `-c copy` to remux without re-encoding when the codecs fit the container. |
Sources
From Converters (FFmpeg, ImageMagick, Pandoc, LibreOffice), Just Solve the File Format Problem (File Formats Wiki), PRONOM, Wikidata. Updated 2026-10-24.