Free online W64 to AU converter

Source format: W64

W64 is an audio file format used by Wave64, a Sony-designed extension of the standard WAV container. It is mainly used in professional audio production and editing workflows where very large recordings are common. The key advantage of W64 over classic WAV is that it supports files larger than 4 GB, which makes it useful for long multitrack sessions, high-resolution recordings, and archival masters.

W64 files are typically handled by audio editors, DAWs, and mastering tools that need a robust uncompressed PCM container. Because it is less common than WAV, some consumer players and older software may not open it directly.

Target format: AU

AU is an older audio container format originally associated with Sun and Unix systems. It is widely recognized by legacy Unix tools and some audio utilities. AU files often store PCM audio, and in some cases may use simple compression schemes depending on the encoder.

The main advantages of AU are its simplicity and compatibility with older Unix-based software. It is still useful for interoperability with legacy systems, basic audio exchange, and certain technical workflows where a straightforward audio container is sufficient.

How to perform the conversion

The most reliable way to convert W64 to AU is with a desktop audio tool such as FFmpeg or Audacity. If you want a quick browser-based option, you can also convert the file on 101convert.com for free without installing any software.

Using FFmpeg

1. Install FFmpeg if it is not already available on your system.
2. Open a terminal or command prompt in the folder containing the W64 file.
3. Run a command such as ffmpeg -i input.w64 output.au.
4. Check the output file in an audio player or editor that supports AU.

If you need to control the audio encoding more explicitly, you can specify the codec. For example, PCM output is commonly used for AU compatibility: ffmpeg -i input.w64 -c:a pcm_s16be output.au.

Using Audacity

1. Open the W64 file in Audacity.
2. Choose File → Export → Export Audio.
3. Select AU as the output format if available in your build.
4. Choose the desired sample format and save the file.

Using 101convert.com

1. Open the conversion page for W64 to AU on 101convert.com.
2. Upload the W64 file.
3. Select AU as the target format if prompted.
4. Start the conversion and download the resulting file.

Notes on quality, compatibility, or limitations

W64 is usually uncompressed, so converting to AU does not improve audio quality; it only changes the container and possibly the sample encoding. If the AU output uses PCM, the conversion can be effectively lossless in terms of audio data. However, if the converter changes bit depth, endianness, or sample rate, the result may differ from the source.

Compatibility is the main concern. AU support is not universal in modern consumer software, and some applications may only accept specific AU variants such as PCM. Also, AU is less suitable than WAV or FLAC for modern workflows because it is older and more limited. If your goal is broad playback compatibility, AU may not be the best destination format.

Because W64 can store very large files, be aware that converting to AU may expose size or feature limits in the target encoder or player. For best results, verify the output in the software that will ultimately use the file.