WAV to AU Converter
FileFlip converts WAV 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 a WAV file to AU?#
- Drop your WAV 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 WAV to AU lose quality?#
It depends on what is inside the file. WAV 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 WAV files online?#
Yes, because nothing is uploaded. FileFlip converts WAV 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 WAV to AU actually does to the file#
Converting WAV 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: WAV → 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 a WAV file?#
A WAV file holds digital audio, almost always uncompressed PCM samples, wrapped in Microsoft and IBM's RIFF chunk structure, the same sample encoding used on audio CDs.
Use WAV for recording, editing and mixing, where uncompressed audio and broad software support matter more than file size.
Convert WAV to MP3 or FLAC once editing is finished and the file needs to be distributed, since raw PCM is unnecessarily large for listening rather than production.
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.
WAV to AU questions people ask#
Is WAV a lossless format?
Yes, WAV is lossless in the sense that matters for audio: it stores uncompressed PCM samples with nothing removed and nothing approximated. It isn't compressed at all, so there's no algorithm that could introduce loss, unlike FLAC, which compresses the audio but still decodes back to the exact same samples.
Why are WAV files so much bigger than MP3s?
WAV files are bigger than MP3s because WAV stores every audio sample uncompressed, while MP3 discards sound and compresses what's left to about a tenth of the size. A three-minute song runs roughly 30 MB as CD-quality WAV versus 3-5 MB as a 192 kbps MP3.
Does converting WAV to MP3 lose quality?
Yes, converting WAV to MP3 loses quality, because MP3 is a lossy codec that permanently discards audio data during encoding. The loss is usually inaudible at 256-320 kbps, but it is real and can't be undone by converting the MP3 back to WAV.
What plays WAV files?
Every mainstream media player and DAW plays WAV files: Windows Media Player and VLC on Windows, QuickTime Player and Music on macOS, and Audacity, Pro Tools, Logic and Ableton Live everywhere audio gets edited. Support is effectively universal because the format has been the audio industry's baseline since 1991.