What Is an AMR File?

How to Open, Edit, and Convert AMR Files

AMR Files
AMR Files.

A file with the AMR file extension is an Adaptive Multi-Rate ACELP Codec file. ACELP is a human speech audio compression algorithm that stands for Algebraic Code Excited Linear Prediction.

Therefore, Adaptive Multi-Rate is a compression technology used for encoding audio files that are primarily speech-based, like for cell phone voice recordings and VoIP applications.

To reduce bandwidth usage when there isn't any audio playing in the file, the AMR format uses technologies like Discontinuous Transmission (DTX), Comfort Noise Generation (CNG), and Voice Activity Detection (VAD).

AMR files are saved in one of two formats depending on the frequency range. The methodology and specific file extension for the AMR file might differ because of this. There's more on that below.

Note: AMR is also an acronym for agent message router and audio/modem riser (an expansion slot on a motherboard), but they have nothing to do with the Adaptive Multi-Rate file format.

How to Play an AMR File

Many popular audio/video players will open AMR files by default. This includes VLC, AMR Player, MPC-HC, and QuickTime. To play an AMR file with Windows Media Player might require K-Lite Codec Pack.

Audacity is mainly an audio editor but it does support playing AMR files, and so, of course, it has the added benefit of letting you edit the AMR audio as well.

Some Apple, Android, and BlackBerry devices create AMR files too, and so they should be able to play them without a special app. For example, some Android and BlackBerry devices use the AMR format for voice recordings (the BlackBerry 10, specifically, cannot open AMR files).

How to Convert an AMR File

If the AMR file is pretty small, I recommend using a free online file converter. The best online AMR converter is probably FileZigZag because it can convert the file to MP3, WAV, M4A, AIFF, FLAC, AAC, OGG, WMA, and other formats without having to download the software to your computer.

Another option for converting an AMR file is media.io. Like FileZigZag, media.io runs entirely in your web browser. Just upload the AMR file there, tell it the format you want it to be converted to, and then download the new file to your computer.

In addition to AMR Player from above, which can not only play but also convert AMR files, is a handful of other AMR converters that can be downloaded.

Tip: One program mentioned in those downloadable AMR converters is Freemake Audio Converter, but the company that delivers that program also makes one called Freemake Video Converter. I mention this program because while it is mainly considered a video file converter, it does also support the AMR format. Downloading it may prove to be beneficial in the future if you ever need to convert a video file.

More Information on AMR Files

Any AMR file is in one of these formats: AMR-WB (Wideband) or AMR-NB (Narrowband).

Adaptive Multi-Rate - WideBand files (AMR-WB) files support a frequency range of 50 Hz to 7 Khz and bit rates of 12.65 kbps to 23.85 kbps. They might use the AWB file extension instead of AMR.

AMR-NB files, however, have bit rate of 4.75 kbps to 12.2 kbps and could end in .3GA too.

Still Can't Open Your File?

If you can't seem to get your file to open with the suggestions from above, double-check that you're reading the file extension correctly.

It's easy to confuse it with one that's spelled similarly, but similar file extensions do not mean that the file formats are similar or that they can be used with the same software tools.

For example, the AMP file extension looks an awful lot like AMR but isn't even slightly related. Follow that link to learn more about AMP files if that's the file format you're actually dealing with.

Some other file extensions that might be confused as an AMR file include AMC (AMC Video), AML (ACPI Machine Language), AM (Automake Makefile Template), AMV (Anime Music Video), AMS (Adobe Monitor Setup), and AMF (Additive Manufacturing).

Since the AMR format is based on the 3GPP container format, 3GA is another file extension this format might use. Though 3GA is used for audio, don't confuse it with the 3GP video container format.

In addition to that, and to make it all the more confusing, AMR-WB files that end with AWB, are very similar in spelling to AWBR files that are WriteOnline WordBar files used with Clicker. Again, the two formats have nothing to do with each other and do not work with the same applications.