FLAC to AU Converter

Why convert FLAC to AU?

Moving FLAC audio to AU is about compatibility and size — which players accept the file and how much disk or bandwidth it costs once it gets there. AU (Sun audio file) earns its place here: minimal headers that legacy Unix and Java tooling read directly. FLAC compresses audio losslessly, typically to half the size of WAV with the original waveform fully recoverable. It is the standard for archiving and hi-fi libraries.

FLAC compresses audio losslessly, typically to half the size of WAV with the original waveform fully recoverable. It is the standard for archiving and hi-fi libraries.

When FLAC → AU is the right move

• A player, car stereo or editing app in your workflow refuses FLAC but handles AU.
• You are consolidating a music or recording library into a single format instead of a mix of FLAC and others.
• You need the file to be smaller, or conversely to stop losing quality, when moving from FLAC to AU.

Quality, size and what changes

The audio is decoded and re-encoded, so the running time, channels and sample content stay intact while bitrate and file size follow AU. Going from a compressed FLAC file to any other lossy format is a second generation of compression — start from the highest-quality source you have when it matters, and expect a lossless target to grow the file rather than improve the sound.

What you gain with AU: Minimal headers that legacy Unix and Java tooling read directly.

How it works

Drop your FLAC file above and Morphio decodes it locally, then re-encodes it as AU using WebAssembly + the browser's native codecs. Nothing is ever uploaded — your files stay on your device. Batch as many files as your machine can handle. See exactly how in-browser conversion works.

FLAC to AU — frequently asked questions