Bulk RMI to M4B Converter Online — Free HD Quality
Drag and drop your multiple RMI files into this 100% free online RMI to M4B converter (.rmi to .m4b), and click the Convert button to bulk convert them to M4B format in HD quality. Use the quality slider to fine-tune your M4B output, then download your converted files one by one or as a single ZIP — no signup and no downloads needed, and your original RMI files are removed from our servers right after. Also see:Easy AAC to M4R converter.
Drop your RMI files here to convert to M4B, or click to browse
Converts .rmi to M4B (.m4b) in HD quality — bulk, free, no signup
Choose FilesRMI vs M4B — File Format Comparison
See how RMI and M4B compare across file extension, MIME type, compression, and feature support. Related:Bulk RMI to MP2 tool.
| Feature | RMI | M4B |
|---|---|---|
| File Extension | .rmi | .m4b |
| MIME Type | audio/midi | audio/mp4 |
| Compression Type | Varies | Lossy |
| Metadata Support | Yes | Yes |
What Is RMI Format?
RIFF MIDI — a Windows variant of the MIDI format wrapped in a RIFF container (the same container used by WAV), produced by older Windows Media Player and Cakewalk software. See also:Batch process RMI to WMA.
- Compression: Varies
- Tags & Metadata: Supported
What Is M4B Format?
MPEG-4 Audiobook — AAC audio in an MP4 container with bookmarking support, the standard format for audiobooks on Apple Books, Audible exports, and iPhone podcasts.
- Compression: Lossy
- Tags & Metadata: Supported