What is the AMR file format?
The .amr format is most commonly used for storing speech recorded with mobile phone voice recorders (e.g., smartphones). Recordings stored in this format may be of various lengths; they are usually short, up to several dozen minutes. AMR is characterised by a high level of compression and is dedicated specifically to speech - not general music - compression.
.amr stands for Adaptive Multi-Rate. The format was standardised as a narrowband speech codec by 3GPP in October 1999 (AMR-NB), with a wideband variant introduced in 2001 that is stored with the .awb extension. AMR-NB encodes narrowband signals in the 200-3400 Hz range. Bit rates vary between 4.75 and 12.2 kbps, and by utilising link adaptation, the codec selects one of 8 available bit rates depending on link conditions - making it well suited to the variable-quality radio links of mobile networks.
A standard .amr file begins with the 6-byte ASCII magic string #!AMR followed by a newline (0x0A). The MIME type is audio/amr. AMR audio is also frequently embedded inside .3gp multimedia containers used by 3GPP-compliant devices; the .3ga extension is used by some Samsung and Sony handsets for standalone AMR audio files.
To open an .amr file on a desktop, players such as VLC media player and FFmpeg support the format on Windows, macOS, and Linux.
Security & safety
RISK: LOWAn .amr file is passive audio data and safe to open in a real media player. The practical risks are external: 'AMR to MP3' searches surface ad-heavy converter sites and fake 'AMR players' that bundle PUP/adware - prefer VLC or FFmpeg, or a reputable in-browser converter. On Windows specifically, do NOT install Apple QuickTime to play AMR: it was discontinued in 2016 and has unpatched security holes. Voice recordings can also be sensitive/private - handle accordingly.
Format details
in a nutshellPrograms that open AMR files
Windows3 apps
VLC media player
Open-source Media > Open File > select the .amr to play it. The reliable free choice on modern Windows. 
FFmpeg
Open-source Play (ffplay) or convert: 'ffmpeg -i note.amr note.mp3'. The most dependable AMR decoder/converter. 
macOS2 apps
Linux2 apps
Android1 app
VLC for Android
Open-source Open the .amr from a file manager. Android also plays AMR natively (it's a system codec). Technical details
deep spec| Codec variants | AMR-NB (narrowband, .amr) and AMR-WB (wideband, .awb); the .amr extension typically stores AMR-NB data |
| File magic bytes | "#!AMR" + newline (hex 23 21 41 4D 52 0A) at byte offset 0; wideband files use "#!AMR-WB\n" |
| MIME type | audio/amr |
| Frequency range (AMR-NB) | 200-3400 Hz (telephone narrowband quality) |
| Sample rate (AMR-NB) | 8 000 Hz |
| Bit rates (AMR-NB) | 8 modes: 4.75, 5.15, 5.9, 6.7, 7.4, 7.95, 10.2, 12.2 kbps |
| Bit-rate adaptation | Link-adaptive; one of 8 bit-rate modes is selected per 20 ms frame based on radio channel conditions |
| Frame duration | 20 ms per speech frame |
| Compression method | Lossy; CELP (Code-Excited Linear Prediction) based |
| AMR-WB parameters | 50-7000 Hz, 16 000 Hz sample rate, 6.6-23.85 kbps in 9 modes; stored as .awb or inside .3gp |
| Multichannel support | Multichannel AMR-NB files use the extended magic header "#!AMR_MC1.0\n" instead of the standard single-channel header |
| Standardisation body | 3GPP (TS 26.071); codec developed by Ericsson, Nokia and others; adopted by ETSI and ITU-T |
| Container embedding | AMR audio is embedded natively in .3gp and .3ga containers (same codec data, different wrapper) |
| Typical applications | Mobile voice notes, 2G GSM / 3G WCDMA cellular voice coding, VoIP |
| Compression efficiency | Achieves intelligible speech at 4.75 kbps, enabling transmission over very narrow radio channels |
| Released | AMR-NB adopted by 3GPP in 1999; AMR-WB (.awb) in 2001 |
| Open standard | Yes · royalty-free |
| Specification | www.3gpp.org |
AMR conversions
Community Q&A
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