AU → M4B
Convert AU audio to M4B entirely in your browser — no upload, no watermark, no sign-up.
Drop files here
or browse from your device
images · audio · video · documents · archives · up to ~500MB
100% Private
Runs in your browser. No upload.
Instant
No queue, no server roundtrip.
Offline-ready
Works after first load.
AU is a Sun-era audio format that survives in old Unix and academic archives and almost nowhere else. M4B is the audiobook format Apple Books and podcast apps bookmark, resume and chapter properly, so converting turns a file you are stuck with into one you can actually use. Morphix runs the whole AU → M4B conversion locally with WebAssembly, so even confidential material never leaves your device.
Drop your AU file above and Morphix decodes it locally, then re-encodes it as M4B 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.
Keep your files & browsing private — get NordVPN