AU to ZIP Converter
Processing entirely on your device — large files may take a moment.
Sun Microsystems Audio and ZIP Archive exist for different jobs: AU is the µ-law audio format of old Unix systems and Java applets — tiny mono files from another era. ZIP is the safest archive to share — no special software needed on the receiving end.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How AU compares to ZIP
| AU | ZIP | |
|---|---|---|
| Compression | µ-law or PCM | Deflate / store |
| Best for | Old system sounds and recordings | Universal sharing |
How to convert AU to ZIP
- 1
Select your files
Select your AU file — it never leaves your device.
- 2
Convert instantly
The engine packs the file, byte for byte, into a ZIP container — no re-encoding, no quality change.
- 3
Download results
Download the finished 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 ZIP format
ZIP (PKWARE, 1989) is the archive format the world agreed on: per-file Deflate compression (or plain store), a central directory that lets tools list and extract single files without touching the rest, and thirty-five years of universal support. Windows, macOS, Linux, phones and browsers all open ZIP natively.
Its compression ratio is middle-of-the-road next to 7z, and its encryption story is genuinely mixed: the classic ZipCrypto is broken, while AES-256 works only in tools that opted in. For maximum compatibility of everyday sharing, though, ZIP remains the only safe answer.
+Strengths
- ✓Opens natively on every platform
- ✓Random access: extract one file, skip the rest
- ✓Thirty-five years of tooling maturity
!Limitations
- −Weaker compression than 7Z/RAR
- −Classic encryption (ZipCrypto) is broken
- −No built-in recovery records
Why convert AU to ZIP?
Think of it as moving your file to the container that fits the job. µ-law flavor sounds dated and mono ZIP works differently: Opens natively on every platform If any of that sounds like your task, run the conversion — it takes seconds and nothing leaves your device.
Frequently asked questions
Is this AU to ZIP 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 ZIP?
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.
Can I convert a whole folder of AU files?
You can select many files at once and they are processed in a single batch. Output files land in one ZIP download when there is more than one result.
Will converting AU to ZIP reduce audio quality?
If ZIP is lossless, the output contains everything the AU file contains — no further loss is added. If ZIP 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.