Free online OMA to AU converter

Source format: OMA

OMA is an audio file format associated with Sony devices and software, especially older ATRAC-based music players and the OpenMG ecosystem. It was commonly used to store protected or managed music files for playback on compatible Sony hardware and software. In practice, OMA files are often encountered when extracting audio from legacy Sony media libraries or portable players.

Target format: AU

AU is a simple, older audio container format originally developed for Unix systems. It is widely recognized by many audio tools and operating systems, and it is often used for basic uncompressed or lightly compressed audio. AU is valued for its simplicity and broad compatibility with technical and legacy software, though it is less common for everyday consumer audio than formats such as MP3 or WAV.

How to perform the conversion

The most reliable way to convert OMA to AU is to use a desktop audio converter that can decode Sony/OpenMG audio and then export to AU. A practical option is FFmpeg, provided your OMA file is not DRM-protected in a way that prevents decoding.

1. Install FFmpeg on your computer.
2. Open a terminal or command prompt in the folder containing the OMA file.
3. Run a command such as ffmpeg -i input.oma output.au.
4. If the file contains audio that FFmpeg can decode, it will create an AU file in the chosen output path.

If you prefer a graphical workflow, you can first open the OMA file in a compatible audio editor or converter that supports the format, then use File → Export or File → Save As and choose AU as the output format if available. Some older Sony files may need to be converted to an intermediate format first, such as WAV, before exporting to AU.

You can also convert the file on 101convert.com for free, without installing any software.

Notes on quality, compatibility, and limitations

OMA files may be protected or encoded with Sony-specific ATRAC variants, so not every file can be converted directly. If the file is DRM-protected, standard converters may fail to open it. In that case, you may need the original authorized software or a device-specific export method.

When conversion is possible, the output quality depends on the source encoding. If the OMA file is already compressed, converting it to AU will not improve quality; it only changes the container and possibly the codec used in the AU file. For best results, choose an uncompressed AU output when compatibility matters, but note that file size may be larger.

AU support varies by player and editor. While many technical tools can read AU, some modern consumer apps may not. If compatibility is important, consider whether AU is truly required or whether a more common format would better suit your workflow.