Convert AIFC to CAF — Free Online Tool
Convert AIFC files to Apple's Core Audio Format (CAF), transcoding the big-endian PCM or compressed audio from AIFC into little-endian PCM_S16LE inside a CAF container. CAF was purpose-built by Apple to replace AIFF's limitations, offering support for files larger than 4GB and a broader codec ecosystem — making it the modern choice for macOS and iOS audio workflows.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your AIFC file here
or click to browse
Free — no uploads, no signups. Your files never leave your browser.
Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
AIFC stores audio in big-endian byte order (a legacy of classic Macintosh hardware), using codecs like PCM_S16BE, PCM_S24BE, or optionally compressed formats like A-law and µ-law. During conversion, FFmpeg reads the AIFC container, decodes the audio stream, and re-encodes it as PCM_S16LE — the little-endian equivalent — inside a CAF container. This byte-order swap is the key transformation: the audio data itself is mathematically identical, but the byte arrangement changes to match the endianness expected by modern Intel and Apple Silicon hardware. The audio passes through a full decode-and-re-encode cycle rather than a simple remux, because AIFC's native big-endian PCM codecs are not directly supported inside CAF.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary, the open-source multimedia processing engine that powers this conversion both in the browser (via FFmpeg.wasm) and on the desktop command line. |
-i input.aifc
|
Specifies the input file — an AIFC audio container which may hold big-endian PCM audio (such as pcm_s16be or pcm_s24be) or compressed audio variants like A-law or µ-law. |
-c:a pcm_s16le
|
Sets the audio codec for the output to 16-bit signed little-endian PCM, which is the standard uncompressed PCM format inside a CAF container and is natively compatible with Apple's Core Audio framework on modern Intel and Apple Silicon Macs. |
-b:a 128k
|
Specifies a 128kbps audio bitrate target. For PCM_S16LE this flag has no practical effect since uncompressed PCM bitrate is determined by sample rate and channel count, not a compression target — it becomes relevant if you switch to a compressed codec like AAC. |
output.caf
|
Defines the output filename and signals FFmpeg to wrap the encoded audio in a CAF (Core Audio Format) container, Apple's modern successor to AIFF that supports large files and the full range of Core Audio codecs. |
Common Use Cases
- Migrating a legacy Mac audio archive of AIFC files recorded in classic Pro Tools or older Logic versions into CAF for use in modern macOS Core Audio applications
- Preparing AIFC telephony recordings (encoded with A-law or µ-law) for ingestion into iOS audio frameworks that expect CAF-wrapped PCM
- Bypassing the 4GB AIFF/AIFC file size ceiling for very long uncompressed audio sessions by converting to CAF, which has no such limit
- Converting big-endian AIFC master files to CAF so they can be directly imported into GarageBand, Logic Pro X, or Xcode audio asset pipelines without format negotiation errors
- Archiving AIFC broadcast audio deliverables into CAF for long-term storage on Apple-centric media servers that index and stream CAF natively
Frequently Asked Questions
If your source AIFC file uses PCM_S16BE (16-bit big-endian PCM), there is absolutely no quality loss — the conversion is a lossless byte-order swap, not a lossy transcode. However, if your AIFC source uses a higher bit depth like PCM_S24BE or PCM_S32BE, downconverting to PCM_S16LE will reduce dynamic range from 24/32-bit to 16-bit, which is a lossy step. In that case, consider changing the output codec to pcm_s24le or pcm_s32le in the FFmpeg command to preserve full bit depth.
AIFC was developed by Apple in the era of Motorola 68000 and PowerPC processors, which are big-endian architectures — meaning the most significant byte comes first. CAF, introduced in 2005, was designed to target modern Intel processors (and later Apple Silicon running in little-endian mode), so it defaults to little-endian PCM. This endianness difference is why you cannot simply rename or remux an AIFC file to CAF; the raw audio bytes must be reordered.
Basic AIFC metadata fields (such as name, author, and copyright chunks from the AIFF/AIFC specification) may not map cleanly into CAF's metadata structure during FFmpeg conversion, and some fields could be silently dropped. CAF has its own metadata chunk format. If metadata preservation is critical, verify the output with a tool like afinfo on macOS after conversion. Loop markers and instrument chunks embedded in AIFC are particularly likely to be lost.
Yes. CAF supports a wider range of codecs than AIFC, including AAC, FLAC, Opus, Vorbis, and higher bit-depth PCM variants like pcm_s24le and pcm_s32le. To use AAC at 256kbps for example, change the command to: ffmpeg -i input.aifc -c:a aac -b:a 256k output.caf. For a lossless but compressed output, use -c:a flac, which will ignore the -b:a bitrate flag since FLAC is lossless.
On macOS or Linux, you can run a shell loop: for f in *.aifc; do ffmpeg -i "$f" -c:a pcm_s16le "${f%.aifc}.caf"; done. On Windows Command Prompt, use: for %f in (*.aifc) do ffmpeg -i "%f" -c:a pcm_s16le "%~nf.caf". This applies the same conversion parameters to every AIFC file in the current directory and names each output after the original file.
If the source AIFC is uncompressed PCM_S16BE and the output is PCM_S16LE, the file sizes will be nearly identical — only the container overhead differs slightly. If your AIFC source uses compressed codecs like A-law or µ-law (which are 8-bit compressed formats), converting to PCM_S16LE will roughly double the file size because uncompressed 16-bit PCM stores more data per sample. Choosing a compressed CAF codec like AAC or FLAC would keep the output file significantly smaller.
Technical Notes
The AIFC-to-CAF conversion involves a mandatory full decode cycle because no AIFC big-endian PCM codec is directly packable into a CAF container — CAF's PCM tracks are little-endian by specification. FFmpeg handles this transparently via its internal PCM decoder/encoder pipeline with no intermediate lossy step for 16-bit sources. One important limitation to be aware of: AIFC supports compressed audio via Apple's proprietary MACE 3:1 and MACE 6:1 codecs; if your source file uses these legacy codecs, FFmpeg may fail to decode them as they have limited support in modern builds. A-law and µ-law AIFC files decode reliably, and their CAF equivalents (pcm_alaw, pcm_mulaw) are directly supported if you wish to keep the compressed format rather than expanding to PCM_S16LE. CAF's major architectural advantage over AIFC is the removal of the 4GB file size limit that affects AIFC (inherited from AIFF), making CAF the correct choice for high-sample-rate or multi-hour uncompressed recordings. Channel layout metadata may also differ between formats; verify multichannel files post-conversion to ensure speaker assignments are correctly interpreted.