Convert M4B to AAC — Free Online Converter

Converting M4B to raw AAC extracts the audio bitstream from the audiobook container, stripping away chapters, bookmarks, and metadata. The result is a bare AAC (ADTS) file containing only the audio data. Since M4B internally uses AAC encoding (typically at 32-64 kbps for spoken word), this conversion can be a lossless stream copy — the same AAC frames are simply unwrapped from the M4B container into a raw ADTS stream.

Some audio processing pipelines, streaming ingest systems, and broadcast multiplexers require raw AAC elementary streams rather than containerized audio. If you need to feed audiobook audio into an HLS segmenter, MPEG-TS multiplexer, or an audio analysis tool that works at the bitstream level, extracting raw AAC from M4B is the necessary first step.