AMR → M4B
Convert AMR audio to M4B entirely in your browser — no upload, no watermark, no sign-up.
Drop files here
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images · audio · video · documents · archives · up to ~500MB
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Runs in your browser. No upload.
Instant
No queue, no server roundtrip.
Offline-ready
Works after first load.
AMR is the narrowband codec old phones recorded voice memos in, and barely anything plays it today. 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 AMR → M4B conversion locally with WebAssembly, so even confidential material never leaves your device.
Drop your AMR 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.
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