Adaptive Multi-Rate audio .amr
A speech audio format commonly used in mobile recordings.
Server processing uses engines we host. Availability depends on the deployed engine and supported file variant.
AMR file format guideAMR to M4B converter
Convert Adaptive Multi-Rate audio (.amr) to M4B for free. Choose files, review the available settings and download your results. No account needed.
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MPEG-4 audiobook .m4b
An MPEG-4 audio container commonly used for audiobooks and spoken-word recordings.
Output uses AAC. Chapters, bookmarks, cover art and DRM are not retained.
M4B file format guideHow to convert AMR to M4B
- Select AMR files from your device or drag them into the converter.
- Check the M4B output. Open conversion settings if you want to make adjustments.
- Convert, compare the original and result, then download your files.
Quality, compatibility and file limits
Available codecs and input streams determine support. Output uses a fixed encoding profile.
Processing uses your device when possible and our servers when required. Browser files are limited to 256 MB each; server conversions to 64 MB; browser spreadsheets to 32 MB. Previews show supported content and do not guarantee identical rendering in every application.