amr

.amrAdaptive Multi-Rate

3GPP (3rd Generation Partnership Project) · 1999

Developer
3GPP (3rd Generation Partnership Project)
Category
Audio
MIME Type
audio/amr
First Released
1999
Open Format
Yes
File Signature
N/A (May start with 0x23 0x41 for AMR-WB, but not a common identifier)
At a Glance
.amr
Adaptive Multi-Rate

The Adaptive Multi-Rate (AMR) audio codec is a speech-oriented audio data compression format.

Reviewed on April 28, 2026
Compression
Varies
Transparency
N/A
Editability
Medium
Best for
audio playback

Key Features

  • Varies storage behavior for typical audio workflows
  • Common MIME type: audio/amr
  • Recognizable file signature: N/A (May start with 0x23 0x41 for AMR-WB, but not a common identifier)
  • Associated with 3GPP (3rd Generation Partnership Project)

Best For

  • Listening across devices
  • Portable sharing
  • Streaming-friendly audio

Less Ideal For

  • Multi-track session editing
  • Complex project packaging
  • Image or document workflows

Common Use Cases

  • Music playback
  • Podcasts and spoken recordings
  • Sharing sound files online

How to Open It

  1. On Windows, open the file with VLC Media Player or Foobar2000.
  2. On macOS, open the file with VLC Media Player or QuickTime Player.
  3. If the file does not open, confirm that the extension really matches .amr and that the download or transfer completed without corruption.

What is a .amr file?

The Adaptive Multi-Rate (AMR) audio codec is a speech-oriented audio data compression format. It is widely used in mobile phones for voice calls due to its ability to adapt its bit rate to the network conditions. This results in a good balance between audio quality and bandwidth efficiency.

Programs That Open .amr Files

PlatformProgram
WindowsVLC Media PlayerFree
Foobar2000Free
Windows Media PlayerFreeOfficial
macOSVLC Media PlayerFree
QuickTime PlayerFreeOfficial
MPlayerXFree

Common Problems with .amr Files

⚠️ File won't play on a specific device or software.
Ensure the device or software supports the AMR codec. You may need to convert the file to a more widely supported format like MP3 or AAC using a converter tool.
⚠️ Poor audio quality.
This can sometimes happen if the AMR file was encoded with a very low bitrate. Converting to a higher bitrate format or re-encoding the AMR file with a better bitrate may help.
⚠️ File corruption.
If the AMR file is corrupted, it might be unplayable. Try re-downloading or obtaining the file again from the source. If possible, attempt repair with specialized audio recovery software.

Frequently Asked Questions

What is an AMR file?

An AMR file is an audio file that uses the Adaptive Multi-Rate codec, primarily designed for speech compression and widely used in mobile communications.

Can I convert AMR files to MP3?

Yes, you can convert AMR files to MP3 or other audio formats using various online converters or desktop software like VLC Media Player or dedicated audio converters.

Why does my AMR file sound bad?

The audio quality of an AMR file depends on the bitrate it was encoded with. Low bitrates, common in mobile calls, can result in lower fidelity. Converting to a higher bitrate format or re-encoding might improve quality if the original encoding allowed for it.

Technical Details

AMR files typically contain audio data encoded using the AMR narrowband or wideband speech codecs. The header signature is often absent, but files might begin with the Magic number '0x23' followed by '0x41' ('#A' in ASCII) for the AMR-WB format.

Did You Know?

AMR was developed by a partnership of Ericsson, Nokia, and VoiceAge.
It is an open standard defined by the 3GPP.
AMR-NB (Narrowband) is commonly used for voice calls, while AMR-WB (Wideband) offers higher fidelity.

Security Information

AMR files themselves are audio data and do not inherently contain malicious code. However, like any file, they can be a vector for malware if they are part of a malicious download or attached to a phishing email. Always ensure you are downloading AMR files from trusted sources.

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