What Is an AMR File?

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 might differ because of this. There’s more on that below.

How to Play an AMR File

Many popular audio/video players open AMR files by default. VLC is a perfect option because it accepts a ton of other formats, too, so it can serve as your audio/video player for basically any file you throw at it. Plus, it’s cross-platform, so it will run on Windows, Mac, and Linux. Some other options include AMR Player, MPC-HC, and QuickTime. Media Player in newer versions of Windows, like Windows 11, should have no problem playing the file, but in older versions, you might need K-Lite Codec Pack. Audacity is mainly an audio editor, but it does support playing the file, and of course, it has the added benefit of letting you edit the audio as well. Some Apple, Android, and BlackBerry devices create AMR files for voice recordings, so they should be able to play them without a special app.

How to Convert an AMR File

If the file is pretty small, we 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 is media.io. Like FileZigZag, it runs entirely in your web browser. Just upload the file there, tell it the format you want it to be converted to (it even supports MP4 and other video formats), and then download the new file to your computer. In addition to AMR Player from above, which can not only play but also convert this format, is a handful of other audio converters that can be downloaded, like MediaHuman’s converter.

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

Still Can’t Open It?

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 don’t mean the file formats are similar or that they can be used with the same software tools. Some file extensions that might be confused for this one include AMP (Adobe Photoshop Curves Map), AMC (AMC Video), AML (ACPI Machine Language), AM (Automake Makefile Template), AMV (Anime Music Video), CAMREC, AMS (Adobe Monitor Setup), and AMF (Additive Manufacturing). Since this format is based on the 3GPP container format, 3GA is another file extension this format might use. 3GA is used for audio, so 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 don’t work with the same applications.