Convert RM to AMR — Free Online Converter
Convert RealMedia (.rm) to Adaptive Multi-Rate Audio (.amr) online for free. Fast, secure video conversion with no watermarks or registration....
Secure Transfer
HTTPS encrypted uploads
Privacy First
Files auto-deleted after processing
No Registration
Start converting instantly
Works Everywhere
Any browser, any device
How to Convert
Upload your .rm file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .amr file when it's ready.
About RM to AMR Conversion
AMR (Adaptive Multi-Rate) is a narrowband speech codec developed by Ericsson for GSM cellular networks, encoding voice at 4.75 to 12.2 kbps. It was designed exclusively for speech — music, sound effects, and ambient audio are heavily distorted. RM (RealMedia) files from the late 1990s contain multimedia audio encoded with RealAudio codecs that, while low quality by modern standards, still far exceed AMR's narrow scope.
Converting RM to AMR is an extreme compression operation that strips audio down to voice-only fidelity. This conversion makes sense only for speech content — converting RM music recordings to AMR destroys any remaining musical quality. AMR's value lies in producing the smallest possible audio files for voice messaging and legacy mobile applications.
Why Convert RM to AMR?
AMR remains the standard codec for voice messages on GSM networks and some messaging apps. If RM files contain speech recordings (lectures, interviews, news broadcasts, voice memos) that need to be shared via MMS or legacy mobile messaging systems, AMR is the required format. The extreme compression — often producing files under 1 KB per second of audio — enables transmission over the slowest mobile connections.
This conversion is purely functional, not qualitative. RM audio already suffers from aggressive dial-up era compression. AMR applies even more aggressive compression on top of that. The only valid use case is when AMR format is specifically required by the target system or device.
Common Use Cases
- Extracting speech from RM interview recordings for MMS sharing on cellular networks
- Converting RM lecture snippets into ultra-compact AMR files for basic phone playback
- Creating voice message files from RM news clip audio for legacy mobile messaging systems
- Producing minimal-size audio samples from RM archives for bandwidth-constrained environments
- Converting RM voice recordings for use in IVR telephone systems that require AMR input
How It Works
FFmpeg demuxes the RM container and decodes the RealAudio stream to PCM. The audio is then downsampled to 8 kHz mono (AMR's fixed requirement) and encoded using the AMR-NB encoder at 12.2 kbps (the highest AMR quality mode). All frequency content above 3.4 kHz is discarded, and stereo is collapsed to mono. The resulting file is extremely small but retains only speech intelligibility.
Quality & Performance
AMR encoding destroys virtually all audio quality beyond basic speech intelligibility. Frequencies above 3.4 kHz are cut entirely, stereo is collapsed to mono, and the 12.2 kbps bitrate produces robotic-sounding audio. Combined with the quality already lost in the original RM encoding, the result is barely adequate for understanding spoken words. Music, sound effects, and ambient audio become unrecognizable. This conversion is appropriate only when AMR format is specifically required.
Device Compatibility
| Device | RM | AMR |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No | No |
Recommended Settings by Platform
YouTube
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
TikTok
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Twitter/X
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Discord
Resolution: 1280x720
Bitrate: 4 Mbps
8MB free, 50MB Nitro
Tips for Best Results
- 1Only use AMR for speech content — for music or general audio from RM sources, use AAC or MP3 instead.
- 2Use AMR-WB (wideband) if the target device supports it — the quality improvement over AMR-NB is substantial for speech.
- 3Pre-process the RM audio with noise reduction before AMR encoding — AMR handles clean speech much better than noisy recordings.
- 4Test with a short clip first — AMR's extreme compression combined with RM's low source quality can produce unintelligible results.
- 5If the target is a modern smartphone, skip AMR entirely and use AAC at 64 kbps — it produces far better quality at similar file sizes.
RM to AMR conversion is a specialized operation for speech-only content requiring the smallest possible file size. It should not be used for music or general audio — the combined quality loss from RM encoding plus AMR re-encoding leaves only basic speech intelligibility.