Interchange File Format (IFF) is the Amiga multimedia container format used for audio, images, and 3D data on Commodore systems.
MPEG-4 Audio Book (M4B) is an AAC-based format with chapter markers, designed specifically for audiobooks and long-form listening.
Reach for IFF when your priority is amiga audio, legacy multimedia, mod music — its uncompromising quality ensures every detail is preserved.
Reach for M4B when your priority is audiobooks, podcasts with chapters — its efficient compression makes sharing fast and storage minimal.
Learn more about IFF and M4B formats in our detailed guide.
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.iff,.IFF (max 100MB)
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IFF (IFF audio) - Interchange File Format, Amiga/Commodore multimedia container. Best for amiga audio, legacy multimedia, mod music.
M4B (M4B audiobooks) - MPEG-4 Audio Book, AAC with chapter support. Ideal for audiobooks, podcasts with chapters.
Yes, GoConvertFile offers free conversion of IFF to M4B for files up to 100MB. No registration required.
Most IFF to M4B conversions complete within seconds for standard-sized files. Larger files may take longer depending on the conversion complexity.
M4B is ideal for audiobooks, podcasts with chapters. MPEG-4 Audio Book, AAC with chapter support
Yes, converting IFF to M4B uses lossy compression, which reduces file size by discarding some visual data. Set quality to 85-95% for a good balance of quality and file size.
M4B files are typically 50-80% smaller than IFF files because M4B uses efficient lossy compression. The exact reduction depends on quality settings.