AU to APK Converter
Processing entirely on your device — large files may take a moment.
Repack an APK as ZIP to inspect its manifest and assets (not for reinstalling). If your files are still in AU format, this page is the shortcut: AU is the µ-law audio format of old Unix systems and Java applets — tiny mono files from another era.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How AU compares to APK
| AU | APK | |
|---|---|---|
| Compression | µ-law or PCM | DEFLATE / stored |
| Best for | Old system sounds and recordings | App inspection |
How to convert AU to APK
- 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 APK container — no re-encoding, no quality change.
- 3
Download results
Download the finished APK 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 APK format
An APK is Android’s install package: a ZIP holding AndroidManifest.xml, compiled DEX bytecode, native libraries and assets. Unpacking one is the standard first step of security review, compatibility checks and asset recovery.
One honest limit: unpacking is inspection, not installation — a repacked ZIP cannot be installed back onto a phone, and the page says so.
+Strengths
- ✓Everything an Android app ships
- ✓ZIP-based, easy to unpack
- ✓Manifest readable as XML
!Limitations
- −DEX bytecode is not human source
- −Repack cannot reinstall
Why convert AU to APK?
There is a concrete reason this conversion exists: µ-law flavor sounds dated and mono APK sidesteps that — Everything an Android app ships If that is your situation, the tool above settles it in seconds, entirely on your device.
Frequently asked questions
Is this AU to APK 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 APK?
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 APK reduce audio quality?
If APK is lossless, the output contains everything the AU file contains — no further loss is added. If APK 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.