# Convert RMVB to M4B

> Convert RMVB to M4B online for free in seconds. Files are processed in a secure, isolated sandbox and deleted automatically. No sign-up, no watermarks.

URL: https://www.converterrr.com/rmvb-to-m4b

- Runs in an isolated cloud sandbox with FFmpeg: files are deleted automatically, and the job uses cloud credits.
- Engines: FFmpeg (cloud).
- API: available. `POST /api/v1/jobs` with `"output_format": "m4b"` (paid plans).
- More: [Video converter](https://www.converterrr.com/video-converter), [RMVB converter](https://www.converterrr.com/rmvb-converter).

## How to convert RMVB to M4B

1. **Add your RMVB files.** Drag and drop RMVB files onto the converter, paste them, or click to browse. You can add several at once.
2. **Choose M4B.** M4B is already selected. Open Options if you want to change quality, size or metadata.
3. **Convert.** Click Convert. Files are processed in a secure cloud sandbox and are usually ready in seconds.
4. **Download your M4B.** Download each M4B file, or everything at once as a ZIP.

## Good to know

- Only the audio track is kept — the result is an M4B file you can play anywhere. Use Options to pick a bitrate.
- RMVB files are typically used for older shared video files, while M4B is best for audiobooks on Apple Books and other players.
- This conversion runs on FFmpeg in an isolated cloud sandbox. Files are encrypted in transit and deleted automatically.

## RMVB vs M4B

|  | RMVB | M4B |
| --- | --- | --- |
| Full name | RealMedia Variable Bitrate | MPEG-4 Audiobook |
| Type | Video | Audio |
| Extensions | .rmvb | .m4b |
| MIME type | application/vnd.rn-realmedia-vbr | audio/mp4 |
| Best for | older shared video files | audiobooks on Apple Books and other players |
| Properties | legacy format, proprietary | lossy compression |

**RMVB:** RMVB is the variable-bitrate version of RealMedia, once common for sharing TV series.

**M4B:** M4B is an MP4 audio file flagged as an audiobook, supporting chapters and resume position.

## Related conversions

- [RMVB to MP4](https://www.converterrr.com/rmvb-to-mp4) (cloud)
- [MP3 to M4B](https://www.converterrr.com/mp3-to-m4b) (in the browser)
- [RMVB to MP3](https://www.converterrr.com/rmvb-to-mp3) (cloud)
- [MP4 to M4B](https://www.converterrr.com/mp4-to-m4b) (in the browser)
- [RMVB to WebP](https://www.converterrr.com/rmvb-to-webp) (cloud)
- [WAV to M4B](https://www.converterrr.com/wav-to-m4b) (in the browser)
- [RMVB to MOV](https://www.converterrr.com/rmvb-to-mov) (cloud)
- [MOV to M4B](https://www.converterrr.com/mov-to-m4b) (in the browser)
- [RMVB to GIF](https://www.converterrr.com/rmvb-to-gif) (cloud)
- [M4A to M4B](https://www.converterrr.com/m4a-to-m4b) (in the browser)
- [RMVB to WAV](https://www.converterrr.com/rmvb-to-wav) (cloud)
- [WebM to M4B](https://www.converterrr.com/webm-to-m4b) (in the browser)

## Convert RMVB to other formats

[RMVB to MP4](https://www.converterrr.com/rmvb-to-mp4), [RMVB to MP3](https://www.converterrr.com/rmvb-to-mp3), [RMVB to WebP](https://www.converterrr.com/rmvb-to-webp), [RMVB to MOV](https://www.converterrr.com/rmvb-to-mov), [RMVB to GIF](https://www.converterrr.com/rmvb-to-gif), [RMVB to WAV](https://www.converterrr.com/rmvb-to-wav), [RMVB to WebM](https://www.converterrr.com/rmvb-to-webm), [RMVB to MKV](https://www.converterrr.com/rmvb-to-mkv), [RMVB to M4A](https://www.converterrr.com/rmvb-to-m4a), [RMVB to AVI](https://www.converterrr.com/rmvb-to-avi), [RMVB to FLAC](https://www.converterrr.com/rmvb-to-flac), [RMVB to AAC](https://www.converterrr.com/rmvb-to-aac), [RMVB to OGG](https://www.converterrr.com/rmvb-to-ogg), [RMVB to WMV](https://www.converterrr.com/rmvb-to-wmv), [RMVB to Opus](https://www.converterrr.com/rmvb-to-opus), [RMVB to FLV](https://www.converterrr.com/rmvb-to-flv), [RMVB to M4V](https://www.converterrr.com/rmvb-to-m4v), [RMVB to MPEG](https://www.converterrr.com/rmvb-to-mpeg), [RMVB to 3GP](https://www.converterrr.com/rmvb-to-3gp), [RMVB to WMA](https://www.converterrr.com/rmvb-to-wma), [RMVB to MPG](https://www.converterrr.com/rmvb-to-mpg), [RMVB to TS](https://www.converterrr.com/rmvb-to-ts), [RMVB to AIFF](https://www.converterrr.com/rmvb-to-aiff), [RMVB to AMR](https://www.converterrr.com/rmvb-to-amr)

## Convert other formats to M4B

[MP3 to M4B](https://www.converterrr.com/mp3-to-m4b), [MP4 to M4B](https://www.converterrr.com/mp4-to-m4b), [WAV to M4B](https://www.converterrr.com/wav-to-m4b), [MOV to M4B](https://www.converterrr.com/mov-to-m4b), [M4A to M4B](https://www.converterrr.com/m4a-to-m4b), [WebM to M4B](https://www.converterrr.com/webm-to-m4b), [FLAC to M4B](https://www.converterrr.com/flac-to-m4b), [MKV to M4B](https://www.converterrr.com/mkv-to-m4b), [AAC to M4B](https://www.converterrr.com/aac-to-m4b), [AVI to M4B](https://www.converterrr.com/avi-to-m4b), [OGG to M4B](https://www.converterrr.com/ogg-to-m4b), [WMV to M4B](https://www.converterrr.com/wmv-to-m4b), [Opus to M4B](https://www.converterrr.com/opus-to-m4b), [WMA to M4B](https://www.converterrr.com/wma-to-m4b), [FLV to M4B](https://www.converterrr.com/flv-to-m4b), [M4V to M4B](https://www.converterrr.com/m4v-to-m4b), [MPEG to M4B](https://www.converterrr.com/mpeg-to-m4b), [3GP to M4B](https://www.converterrr.com/3gp-to-m4b), [AIFF to M4B](https://www.converterrr.com/aiff-to-m4b), [AMR to M4B](https://www.converterrr.com/amr-to-m4b), [MPG to M4B](https://www.converterrr.com/mpg-to-m4b), [TS to M4B](https://www.converterrr.com/ts-to-m4b), [MTS to M4B](https://www.converterrr.com/mts-to-m4b), [VOB to M4B](https://www.converterrr.com/vob-to-m4b)

## RMVB to M4B: frequently asked questions

### How do I convert RMVB to M4B?

Drop your RMVB file onto the converter above, make sure M4B is selected, and click Convert. When it's done, download the M4B file — it usually takes a few seconds.

### Is it safe to convert RMVB to M4B here?

Yes. Your file is sent over an encrypted connection to an isolated sandbox that's created for your job only, then both the original and the result are deleted automatically.

### Is the RMVB to M4B converter free?

Yes. Cloud conversions like this one use credits, and you get free credits every day (3 without an account, 10 with a free account).

### Will converting RMVB to M4B reduce quality?

M4B is a lossy format, but our defaults are tuned to be visually indistinguishable for most files. You can raise the quality under Options.

### Can I convert multiple RMVB files at once?

Yes. Add up to 5 files at a time without an account, 10 with a free account and up to 500 on paid plans, then download them individually or as a single ZIP.