AU to PCM Converter
Processing entirely on your device — large files may take a moment.
AU is the µ-law audio format of old Unix systems and Java applets — tiny mono files from another era. Convert any audio to raw PCM for DSP pipelines, or wrap a PCM dump into WAV/MP3 to make it playable.
iLoveConverter processes everything locally on your computer, which makes it private and fast: no upload wait, no server storage, no limits. Add as many files as you like — batch conversion is built in.
How AU compares to PCM
| AU | PCM | |
|---|---|---|
| Compression | µ-law or PCM | None (16-bit LE samples) |
| Best for | Old system sounds and recordings | DSP pipelines, embedded audio |
How to convert AU to PCM
- 1
Select your files
Drag & drop your AU files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to PCM". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted PCM file individually, or grab everything at once as a ZIP archive.
About the AU format
AU is Sun Microsystems' audio format from the Unix workstation age: a small header followed by µ-law (or PCM) samples. Java's applet era shipped it everywhere, and old Unix sound tooling still emits it.
Modern players increasingly skip it. Converting AU to WAV preserves the samples bit-for-bit while moving the file into universal territory — the standard rescue path for system sounds and old recordings.
+Strengths
- ✓Simple, lossless sample storage
- ✓Native to old Unix/Java tooling
!Limitations
- −µ-law flavor sounds dated and mono
- −Dropped by modern players
About the PCM format
Raw PCM is audio at its most naked: 16-bit little-endian samples, no header, no metadata, no sample-rate label — just the waveform bytes. It is the lowest common denominator every DSP pipeline, telephony stack and embedded system speaks, which is why exports and lab tools keep asking for it.
Because the file carries no sample-rate information, consumers must agree on the rate out of band (8000 Hz telephony and 48000 Hz video are the common conventions). Wrapping PCM into WAV adds the missing header and makes the bytes playable anywhere.
+Strengths
- ✓Zero overhead — pure sample data
- ✓Universally understood by DSP tools
- ✓Bit-exact lossless representation
!Limitations
- −No header: sample rate must be known out of band
- −Unplayable directly in most apps
Why convert AU to PCM?
Converting makes sense where the strengths of PCM meet what AU cannot give you. Zero overhead — pure sample data Meanwhile µ-law flavor sounds dated and mono One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this AU to PCM converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for AU to PCM?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Will converting AU to PCM reduce audio quality?
If PCM is lossless, the output contains everything the AU file contains — no further loss is added. If PCM is lossy, one recompression pass is unavoidable; the quality slider controls how much. Loss that already happened in the source file can never be undone by converting.
Are tags like title and artist preserved?
Tag handling varies between target formats and this conversion focuses on the audio itself. For archival copies where tags matter, keep the original file; the converted copy is for playback and sharing.