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Convert SPX to AMR
Convert SPX to AMR format — 100% browser-based, no upload required.
2 cores · low tier
Drop a file here or click to select
Format will be auto-detected
About these formats
Source
SPX
Speex AudioOpen-source speech codec designed for voice over IP. Provides good speech compression at very low bitrates.
Best for
VoIPVoice chatSpeech compressionPodcasts
Advantages
- + Optimized for speech
- + Open source
- + Very low bitrate
Limitations
- − Superseded by Opus
- − Speech only
- − Declining usage
Target
AMR
Adaptive Multi-Rate AudioSpeech codec optimized for voice recording. Widely used in mobile phones for voice notes and MMS audio.
Best for
Voice recordingPhone audioMMS messagesLow-bandwidth speech
Advantages
- + Very small files
- + Optimized for speech
- + Mobile standard
Limitations
- − Speech only (poor music)
- − Low quality
- − Limited sample rates