Software & Apps File Types 55 55 people found this article helpful What Is an AMR File? How to open, edit, and convert AMR files by Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated on April 13, 2020 File Types Design Cryptocurrency MS Office Windows Linux Google Drive Apps File Types Backup & Utilities View More Tweet Share Email 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. Lifewire / Derek Abella 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 the file with Windows Media Player might require K-Lite Codec Pack. Audacity is mainly an audio editor but it does support playing the file, and so, of course, it has the added benefit of letting you edit the audio as well. Some Apple, Android, and BlackBerry devices create AMR files, too, 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 for converting it is with 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, 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 converters that can be downloaded. 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. We mention this program because while it's mainly considered a video file converter, it does also support the 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 (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 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 don't 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 for this one include 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.