What is a AMR file?

AMR — mobile voice recording

What is it?

AMR is a format built for one purpose only: the human voice over a phone line. It compresses audio down to a handful of kilobits per second, keeping only the frequencies that carry speech.

Applied to music, the results are dismal — anything that isn't a voice gets mangled beyond recognition. That's expected: it was never designed for that job.

History & origin

AMR was adopted in 1999 by the standards body governing mobile telephony, to carry voice over GSM networks.

It later found its way into voice memos and audio messages on phones from before the smartphone era.

Why it is useful

Files are tiny: an hour of speech fits into just a few megabytes.

It remains perfectly intelligible for what it's meant to do — carry a voice, nothing more.

Limits & drawbacks

Audio quality is very poor, making it unusable for music.

It's an aging format, poorly supported by modern desktop software.

Practical tips

Convert your AMR files to MP3 so you can listen to and archive them comfortably — but don't expect to recover a level of quality that was never in the original file to begin with.

For modern voice recording, Opus does a far better job at a comparable file size.

Convert your AMR in seconds, on our secure servers in France.

Convert a AMR