AU to AIFC Converter
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Supports: AU
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Need help?AU to AIFC Converter
AU (.au / .snd) is the Sun Microsystems audio format that became the default sound type on early Unix workstations, NeXT machines, and the 1990s web. AIFC (AIFF-C) is Apple's compressed-capable variant of AIFF, the long-standing audio container of the Mac and pro-audio world. This converter re-wraps an old Unix .au recording into an Apple-native AIFC file so it opens cleanly in Finder, QuickTime, Logic, and other Core Audio apps.
One honest caveat up front: if your AU file is the classic 8-bit μ-law telephony recording (8 kHz, mono), converting it to PCM-based AIFC does not restore the audio that μ-law threw away. It re-wraps the same degraded signal into a larger, uncompressed container. If the AU already holds 16-bit linear PCM, the conversion is essentially a lossless re-wrap into Apple's format.
AU Format at a Glance
| Property | Value |
|---|---|
| Full name | Sun/NeXT audio (.au, .snd) |
| Origin | Sun Microsystems; common on NeXT and early-web audio |
| File signature | 0x2e736e64 — the four ASCII bytes .snd |
| Typical payload | 8-bit G.711 μ-law (the original default); also 8/16/24/32-bit linear PCM, A-law, ADPCM |
| Original default rate | 8000 Hz, mono μ-law (telephony quality) |
| Byte order | Big-endian header |
| Best for | Legacy Unix/Sun system sounds, archived web-era clips |
AIFC Format at a Glance
| Property | Value |
|---|---|
| Full name | Audio Interchange File Format — Compressed (AIFF-C) |
| Origin | Apple, July 1991 — a superset of AIFF (Apple, 1988), built on the EA IFF chunk model |
| Container | FORM/AIFC chunks, each tagged with a FourCC |
| Payload | Uncompressed PCM (compression type NONE) or a wrapped codec; this tool outputs 16-bit big-endian PCM by default |
| Bit depth | Commonly 16-bit; the format also allows 8/24/32-bit |
| Byte order | Big-endian by default; AIFC also allows little-endian PCM via Apple's sowt |
| Best for | Apple/Mac and pro-audio workflows (QuickTime, Logic, Core Audio) |
How to Convert AU to AIFC
- Upload Your AU File: Drag and drop your
.au/.sndfile onto the page or click "Add Files." You can queue several at once and convert them with the same settings. - Pick an Audio Codec: Open "Show All Options" and choose the codec under Audio Codec — it defaults to PCM 16-bit Big Endian (standard for AIFC); PCM 16-bit Little Endian, PCM A-law, and PCM mu-law are also available.
- Set Audio Channel, Sample Rate, or Trim: Leave Audio Channel and Audio Sample Rate on "Original" to preserve the source, or override them; use Trim to keep only the segment you need.
- Convert and Download: Click "Convert" and save your AIFC file. No sign-up, no watermark. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours.
Frequently Asked Questions
Will converting AU to AIFC improve the audio quality?
No. A converter can only re-package the audio that is already in the file; it cannot add detail that was never recorded or that μ-law compression discarded. If your AU is an 8 kHz μ-law clip, the AIFC output carries the same limited bandwidth in a larger PCM wrapper. The realistic reason to convert is Apple/Mac compatibility, not fidelity.
Is AIFC the same as AIFF?
They share a structure, but AIFF stores only uncompressed PCM, while AIFC (AIFF-C, introduced by Apple in 1991) is a superset that can also wrap compressed codecs. An AIFC file using compression type NONE is, in practice, uncompressed PCM in the AIFF-C container. If you specifically need a plain AIFF file, use our AU to AIFF converter instead.
What bit depth and byte order does the output use?
By default this tool writes 16-bit big-endian PCM, which is the conventional layout for AIFF-family files on Apple systems. You can switch the codec to PCM 16-bit Little Endian, PCM A-law, or PCM mu-law under Audio Codec if a specific workflow requires it.
Why is my AIFC file larger than the original AU?
Because AIFC here stores uncompressed PCM. An 8-bit μ-law AU packs each sample into one byte, whereas 16-bit PCM uses two bytes per sample and adds a full AIFF-C header, so the file roughly doubles or more. In our testing, a 10-second 8 kHz mono μ-law AU (about 80 KB) expanded to roughly 160 KB as 16-bit PCM AIFC. If you want a small, portable file instead, convert to a lossy format with our AU to MP3 converter.
What programs can open an AIFC file?
AIFC opens natively in Apple's QuickTime, Music/iTunes, and Finder preview, and in pro-audio apps such as Logic Pro and GarageBand. On other platforms, Audacity, VLC, and FFmpeg read it as well. AU files, by contrast, are best handled by those same cross-platform tools since few modern Apple apps open .au directly — which is exactly why this conversion is useful.
Are my files kept private?
Yes. Your file is uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours. There is no sign-up, no watermark, and files are never shared or made public.