# Convert M4B to AMR

> Convert M4B to AMR 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/m4b-to-amr

- 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": "amr"` (paid plans).
- More: [Audio converter](https://www.converterrr.com/audio-converter), [M4B converter](https://www.converterrr.com/m4b-converter).

## How to convert M4B to AMR

1. **Add your M4B files.** Drag and drop M4B files onto the converter, paste them, or click to browse. You can add several at once.
2. **Choose AMR.** AMR 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 AMR.** Download each AMR file, or everything at once as a ZIP.

## Good to know

- We encode at a high-quality bitrate by default. Pick a specific bitrate or sample rate under Options.
- M4B files are typically used for audiobooks on Apple Books and other players, while AMR is best for voice recordings from older phones.
- This conversion runs on FFmpeg in an isolated cloud sandbox. Files are encrypted in transit and deleted automatically.

## M4B vs AMR

|  | M4B | AMR |
| --- | --- | --- |
| Full name | MPEG-4 Audiobook | Adaptive Multi-Rate |
| Type | Audio | Audio |
| Extensions | .m4b | .amr |
| MIME type | audio/mp4 | audio/amr |
| Best for | audiobooks on Apple Books and other players | voice recordings from older phones |
| Properties | lossy compression | lossy compression, legacy format |

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

**AMR:** AMR is a speech codec used by mobile phones for voice recordings and calls.

The other way around: [convert AMR to M4B](https://www.converterrr.com/amr-to-m4b).

## Related conversions

- [AMR to M4B](https://www.converterrr.com/amr-to-m4b) (in the browser)
- [M4B to MP3](https://www.converterrr.com/m4b-to-mp3) (in the browser)
- [MP3 to AMR](https://www.converterrr.com/mp3-to-amr) (cloud)
- [M4B to WAV](https://www.converterrr.com/m4b-to-wav) (in the browser)
- [MP4 to AMR](https://www.converterrr.com/mp4-to-amr) (cloud)
- [M4B to M4A](https://www.converterrr.com/m4b-to-m4a) (in the browser)
- [WAV to AMR](https://www.converterrr.com/wav-to-amr) (cloud)
- [M4B to FLAC](https://www.converterrr.com/m4b-to-flac) (in the browser)
- [MOV to AMR](https://www.converterrr.com/mov-to-amr) (cloud)
- [M4B to AAC](https://www.converterrr.com/m4b-to-aac) (in the browser)
- [M4A to AMR](https://www.converterrr.com/m4a-to-amr) (cloud)
- [M4B to OGG](https://www.converterrr.com/m4b-to-ogg) (in the browser)

## Convert M4B to other formats

[M4B to MP3](https://www.converterrr.com/m4b-to-mp3), [M4B to WAV](https://www.converterrr.com/m4b-to-wav), [M4B to M4A](https://www.converterrr.com/m4b-to-m4a), [M4B to FLAC](https://www.converterrr.com/m4b-to-flac), [M4B to AAC](https://www.converterrr.com/m4b-to-aac), [M4B to OGG](https://www.converterrr.com/m4b-to-ogg), [M4B to Opus](https://www.converterrr.com/m4b-to-opus), [M4B to WMA](https://www.converterrr.com/m4b-to-wma), [M4B to AIFF](https://www.converterrr.com/m4b-to-aiff), [M4B to AC3](https://www.converterrr.com/m4b-to-ac3), [M4B to MP2](https://www.converterrr.com/m4b-to-mp2), [M4B to WEBA](https://www.converterrr.com/m4b-to-weba), [M4B to OGA](https://www.converterrr.com/m4b-to-oga), [M4B to MKA](https://www.converterrr.com/m4b-to-mka), [M4B to WV](https://www.converterrr.com/m4b-to-wv), [M4B to AU](https://www.converterrr.com/m4b-to-au), [M4B to TTA](https://www.converterrr.com/m4b-to-tta)

## Convert other formats to AMR

[MP3 to AMR](https://www.converterrr.com/mp3-to-amr), [MP4 to AMR](https://www.converterrr.com/mp4-to-amr), [WAV to AMR](https://www.converterrr.com/wav-to-amr), [MOV to AMR](https://www.converterrr.com/mov-to-amr), [M4A to AMR](https://www.converterrr.com/m4a-to-amr), [WebM to AMR](https://www.converterrr.com/webm-to-amr), [FLAC to AMR](https://www.converterrr.com/flac-to-amr), [MKV to AMR](https://www.converterrr.com/mkv-to-amr), [AAC to AMR](https://www.converterrr.com/aac-to-amr), [AVI to AMR](https://www.converterrr.com/avi-to-amr), [OGG to AMR](https://www.converterrr.com/ogg-to-amr), [WMV to AMR](https://www.converterrr.com/wmv-to-amr), [Opus to AMR](https://www.converterrr.com/opus-to-amr), [WMA to AMR](https://www.converterrr.com/wma-to-amr), [FLV to AMR](https://www.converterrr.com/flv-to-amr), [M4V to AMR](https://www.converterrr.com/m4v-to-amr), [MPEG to AMR](https://www.converterrr.com/mpeg-to-amr), [3GP to AMR](https://www.converterrr.com/3gp-to-amr), [AIFF to AMR](https://www.converterrr.com/aiff-to-amr), [MPG to AMR](https://www.converterrr.com/mpg-to-amr), [TS to AMR](https://www.converterrr.com/ts-to-amr), [MTS to AMR](https://www.converterrr.com/mts-to-amr), [VOB to AMR](https://www.converterrr.com/vob-to-amr), [M2TS to AMR](https://www.converterrr.com/m2ts-to-amr)

## M4B to AMR: frequently asked questions

### How do I convert M4B to AMR?

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

### Is it safe to convert M4B to AMR 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 M4B to AMR 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 M4B to AMR reduce quality?

AMR 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 M4B 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.

### Can I convert AMR back to M4B?

Yes — use our AMR to M4B converter. Note that converting back and forth between formats can't recover detail lost to lossy compression.