AU to AIFC Converter

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

AIFC Format at a Glance

How to Convert AU to AIFC

1. Upload Your AU File: Drag and drop your .au / .snd file onto the page or click "Add Files." You can queue several at once and convert them with the same settings.
2. 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.
3. 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.
4. 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.

What is a .au (.snd) file?

AU is the audio format Sun Microsystems created for its Unix workstations; it also became common on NeXT machines and in the early days of the web, and its files sometimes use the .snd extension. The format is identified by the four-byte signature .snd at the start of the file, and its original default was 8-bit μ-law audio at 8 kHz — telephone quality — though later variants allow linear PCM at higher bit depths.

You will most often meet .au files today as old Unix system sounds or as small clips embedded in 1990s Java applets and web pages, which is why converting one into a current Apple format is usually about compatibility rather than fidelity.

Can I keep the original μ-law encoding in the AIFC instead of PCM?

Yes. Under Audio Codec you can choose PCM mu-law (or PCM A-law) to wrap the companded data much as the AU stored it, rather than expanding it to linear samples. Pick PCM 16-bit Big Endian instead — the default — when you want a standard uncompressed working file for Apple audio tools. Neither choice restores fidelity that μ-law already discarded; they only change how the samples are stored.