Free online BWF to AU converter

Source format: BWF

BWF stands for Broadcast Wave Format, a professional audio file format based on standard WAV. It is widely used in broadcasting, film, television, field recording, and audio post-production. In addition to uncompressed audio, BWF files can store extra metadata such as timecode, scene information, and production notes, which makes them especially useful in professional workflows.

Target format: AU

AU is an older audio file format originally associated with Sun Microsystems and Unix systems. It is simple, widely recognized by many audio tools, and often used for basic audio exchange, legacy systems, and simple playback. AU files may contain uncompressed PCM audio or compressed audio depending on the variant, but they are generally less feature-rich than BWF.

How to perform the conversion

The most reliable way to convert BWF to AU is with a desktop audio tool such as FFmpeg, which preserves audio quality when converting uncompressed sources. If you want to convert the file online, you can use the built-in converter on 101convert.com for free without installing any software.

1. Install FFmpeg if it is not already available on your system.
2. Open a terminal or command prompt in the folder containing the BWF file.
3. Run a command such as ffmpeg -i input.bwf output.au.
4. If you need to control the audio encoding more explicitly, you can use PCM output, for example ffmpeg -i input.bwf -c:a pcm_s16be output.au for a common AU-compatible format.
5. Check the resulting output.au file in an audio player or editor that supports AU.

If you prefer a graphical workflow, audio editors such as Audacity can open many BWF files and export to AU through File → Export → Export Audio, then selecting AU as the output format if available in your build or via supported export options.

Notes on quality, compatibility, and limitations

BWF is usually uncompressed, so converting to AU can preserve audio quality if you choose an uncompressed AU encoding. However, some AU variants and older players have limited support for sample rates, bit depths, or channel counts. Metadata stored in BWF, such as broadcast notes and timecode, is generally not preserved in AU because AU is a much simpler format. If your BWF file uses uncommon channel layouts or high-resolution audio, verify that the target AU encoder and player support it. For archival or professional delivery, AU is usually less suitable than modern formats, but it can still be useful for compatibility with legacy Unix-based tools.