AIFF to AU Converter
FileFlip converts AIFF to AU entirely inside your browser, using FFmpeg compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an AIFF file to AU?#
- Drop your AIFF file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to AU and the conversion starts on its own. FileFlip downloads 30.8 MB of WebAssembly the first time and nothing after that, then runs FFmpeg on your own machine.
- Save the AU file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting AIFF to AU lose quality?#
It depends on what is inside the file. AIFF is a container rather than a codec, so whether the AU conversion copies the streams across untouched or re-encodes them is decided by the codecs that particular file happens to use.
Is it safe to convert AIFF files online?#
Yes, because nothing is uploaded. FileFlip converts AIFF files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What AIFF to AU actually does to the file#
Converting AIFF to AU runs on FFmpeg, downloads 30.8 MB of WebAssembly the first time and nothing after that, re-encodes or copies through depending on the codecs in the file, and drops encoded streams.
| Engine | FFmpeg |
|---|---|
| Conversion path | One step: AIFF → AU |
| Downloaded to your browser | 30.8 MB, once, then cached by your browser |
| Quality | Decided by the codecs inside the file |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Encoded streams | Dropped | The target format has nowhere to put it. |
What is an AIFF file?#
An AIFF file stores uncompressed PCM audio samples in Apple's Audio Interchange File Format, a structure the company built on Electronic Arts' IFF in 1988 for professional and Mac-native audio.
Use AIFF for recording and editing on macOS, where it's the native uncompressed format for tools like Logic Pro and GarageBand.
Convert AIFF to WAV for compatibility with non-Apple software, or to FLAC or MP3 once editing is done and the file needs to be smaller for distribution.
What is an AU file?#
An AU file holds audio in Sun Microsystems' Unix workstation format, a plain header followed by raw sample data that was the standard system-alert and early web audio format before WAV and MP3 took over.
AU still shows up as the format Java's javax.sound and some Unix system tools default to for short sound effects, where its simplicity is the point.
Convert AU to WAV or MP3 when the audio needs to play in modern media players, browsers, or editing software that no longer ship AU support by default.
AIFF to AU questions people ask#
Is AIFF a lossless format?
Yes, AIFF is lossless: it stores raw, uncompressed PCM audio samples with nothing removed or approximated, so what you hear back is identical to what was recorded. Unlike FLAC, standard AIFF doesn't compress the audio at all, so there's no encode-decode step where anything could go wrong.
What's the difference between AIFF and WAV?
AIFF and WAV both store uncompressed PCM audio and are equivalent in quality; the difference is mostly heritage and byte order. AIFF, developed by Apple, stores samples big-endian and is the default on macOS audio tools, while WAV, developed by Microsoft and IBM, stores samples little-endian and is the default on Windows.
Does converting AIFF to MP3 lose quality?
Yes, converting AIFF to MP3 loses quality, because MP3 is a lossy codec that permanently discards audio data during compression, while AIFF is uncompressed. The loss is usually inaudible at a high bit rate like 256-320 kbps, but it is real and can't be undone by converting back to AIFF.
What plays AIFF files?
Apple's Music and QuickTime Player play AIFF natively, as do Logic Pro, GarageBand, Audacity and most professional DAWs on any platform. VLC also plays AIFF on Windows and Linux, though consumer media players and streaming services outside Apple's ecosystem often don't support it at all.