Free online AU to ALAC converter
AU is a legacy Unix audio format; ALAC is Apple’s lossless audio codec.
Convert AU to ALAC online - free
Your file is processed instantly and never stored on our servers.
How to convert au to alac file
- Audio
- No ratings yet.
101convert.com assistant bot
1mo
Source format: AU
AU is a simple audio file format originally associated with Sun Microsystems and early Unix systems. It is often used for basic sound clips, legacy software, and older audio archives. AU files may contain uncompressed PCM audio or compressed audio data, and they are most commonly encountered in technical, educational, or archival contexts rather than modern consumer workflows.
Target format: ALAC
ALAC stands for Apple Lossless Audio Codec. It is a lossless audio format designed to preserve the original audio quality while reducing file size. ALAC is widely used in the Apple ecosystem, including iTunes, Music, iPhone, iPad, and macOS. Its main advantages are full audio fidelity, good compression, and broad compatibility with Apple devices and many modern media players.
How to perform the conversion
The most reliable way to convert AU to ALAC is with FFmpeg, a powerful free desktop command-line tool that supports both formats.
- Install FFmpeg on your computer.
- Open a terminal or command prompt.
- Run a command such as
ffmpeg -i input.au -c:a alac output.m4a. - Check the resulting file in a player that supports ALAC, such as Apple Music, iTunes, or VLC.
If you prefer a simpler workflow, you can also convert the file on 101convert.com for free without installing any software.
In FFmpeg, the -c:a alac option tells the program to encode the audio using Apple Lossless, and .m4a is the most common container for ALAC files.
Notes on quality and compatibility
ALAC is lossless, so the conversion will preserve the audio quality of the source only if the AU file already contains uncompressed or otherwise high-quality audio. If the AU file is compressed or low quality, ALAC will not improve it; it will only store the existing audio more efficiently.
Because AU is an older format, some files may use uncommon sample rates, bit depths, or codecs. If a conversion fails, try first converting the AU file to standard PCM audio and then encoding to ALAC. Also note that ALAC is usually stored in an M4A container, not as a standalone .alac file.
Note: This au to alac conversion record is incomplete, must be verified, and may contain inaccuracies. Please vote below whether you found this information helpful or not.
AU vs ALAC: format comparison
How the AU and ALAC formats compare on the properties that matter most for this conversion.
| Property | .AU Sun/NeXT audio file | .ALAC Apple Lossless Audio Codec |
|---|---|---|
| Compression | Uncompressed | Lossless |
| Audio quality | — | Lossless |
| Metadata support | Basic | Basic |
| Streaming | Yes | Yes |
| DRM protection | No DRM | Optional |
| Opens in a web browser | Partial | No |
| Typical file size | Large | Medium |
| Open standard | Yes | Partly open |
| Best used for | Speech and voice | Music |
| Introduced | 1988 | 2004 |
| Developer | Sun Microsystems / NeXT | Apple Inc. |
| MIME type | audio/basic | audio/alac |
Frequently asked questions
Is the AU to ALAC converter free?
Yes, converting AU to ALAC on 101convert.com is completely free. No registration, email address or installation is required.
How large can my AU file be?
You can upload AU files up to 1000 MB and convert up to 100 files at once in a single batch.
What happens to my uploaded files?
Files are processed automatically and deleted from our servers within a few minutes after conversion. We never view or share your files.
Do I need to install any software to convert AU to ALAC?
No. The AU to ALAC conversion runs entirely online in your browser and works on Windows, Mac, Linux, Android and iPhone.
Did the conversion fail?
In most cases, the cause is an incorrect file format. Please upload a valid AU file for this AU to ALAC conversion. Occasionally, the issue may be on our side. We analyze recurring conversion failures and disable or fix the converter if we detect a defect.