Convert M4B to ALAC — Free Online Converter

Converting M4B to ALAC (Apple Lossless) re-encodes the audiobook's AAC audio into Apple's lossless codec inside an M4A container. Since M4B audiobooks use lossy AAC at 32-64 kbps, the resulting ALAC file preserves the decoded signal losslessly but does not improve upon the original AAC quality. The chapter markers and bookmarking functionality of M4B are lost in the conversion to a standard ALAC M4A file.

Archival of decoded audiobook audio in a lossless format prevents any further generational quality loss if the file needs to be re-encoded in the future. If you plan to process, edit, or re-encode the audiobook audio multiple times, working from an ALAC intermediate avoids cascading lossy-to-lossy degradation. Some audio management systems also categorize ALAC files differently from M4B.