Convert MKV to AMR — Free Online Converter

AMR (Adaptive Multi-Rate) is a narrowband speech codec designed for GSM cellular networks, operating at extremely low bitrates between 4.75 and 12.2 kbps. Converting MKV to AMR makes sense only when you need voice audio for legacy telecom systems, embedded devices, or applications that specifically require AMR input.

AMR was standardized by 3GPP specifically for encoding human speech over cellular networks, and it remains embedded in VoIP gateways, IVR phone systems, and telecom testing equipment. Some legacy Android voicemail apps and older Nokia handsets store and play recordings exclusively in AMR format, so converting MKV audio to AMR may be required for compatibility with these systems.

The format's extremely low bitrate also makes it useful for scenarios where bandwidth is severely limited. A one-minute AMR file at 12.2 kbps occupies only about 90 KB, compared to roughly 1 MB for MP3 at 128 kbps. For automated phone systems that store thousands of hours of voice prompts or call recordings, AMR's compact size keeps storage costs manageable.