MPEG-4 Audio Book (M4B) is an AAC-based format with chapter markers, designed specifically for audiobooks and long-form listening.
Core Audio Format (CAF) is Apple's audio container designed to overcome the file size and sample rate limitations of AIFF and WAV.
Reach for M4B when your priority is audiobooks, podcasts with chapters — its efficient compression makes sharing fast and storage minimal.
Reach for CAF when your priority is apple audio production, professional editing — its uncompromising quality ensures every detail is preserved.
Learn more about M4B and CAF formats in our detailed guide.
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M4B (M4B audiobooks) - MPEG-4 Audio Book, AAC with chapter support. Best for audiobooks, podcasts with chapters.
CAF (CAF audio) - Core Audio Format, Apple's professional audio format. Ideal for apple audio production, professional editing.
Yes, GoConvertFile offers free conversion of M4B to CAF for files up to 100MB. No registration required.
Most M4B to CAF conversions complete within seconds for standard-sized files. Larger files may take longer depending on the conversion complexity.
CAF is ideal for apple audio production, professional editing. Core Audio Format, Apple's professional audio format
No, converting M4B to CAF does not cause additional quality loss — CAF uses lossless compression. However, any artifacts already present in the original M4B file will persist in the CAF output.
CAF files are typically 2-5x larger than equivalent M4B files because CAF preserves all pixel data. This is expected and necessary for lossless quality.