Convert MP3 to M4B Online — Free
Fast, free MP3 to M4B converter. No registration required.
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How to Convert
Upload your .mp3 file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .m4b file when it's ready.
What is MP3?
MP3 is the most popular audio format worldwide. It uses lossy compression to reduce file size while maintaining acceptable audio quality for most listeners.
Format Details
- Full Name
- MPEG Audio Layer III
- Extension
- .mp3
Key Features
- Universal compatibility
- Small file sizes
- Streaming support
- ID3 tag support
What is M4B?
M4B is the MPEG-4 audiobook format used by Apple iTunes and many audiobook platforms. It supports chapter markers, bookmarking, and AAC compression for efficient audiobook delivery.
Format Details
- Full Name
- MPEG-4 Audiobook
- Extension
- .m4b
Key Features
- Chapter support
- Bookmark resume
- iTunes compatible
- AAC compression
MP3 vs M4B
| Feature | MP3 | M4B |
|---|---|---|
| Full Name | MPEG Audio Layer III | MPEG-4 Audiobook |
| Extension | .mp3 | .m4b |
| Best For | Universal compatibility | Chapter support |