Convert AMR to MP3 — call recordings and voice notes
This AMR to MP3 converter turns the .amr files that many phones, call-recorder apps and dictaphones save into ordinary MP3s. Once converted, a recording plays on any computer, can be attached to an e-mail or WhatsApp message, shared with a lawyer, an insurer or a colleague, or dropped into a transcription tool. Drop in one recording or a whole folder and download the MP3s singly or as a ZIP.
AMR (Adaptive Multi-Rate) is the speech codec of GSM, 3G and VoLTE phone calls, which is why call recorders on Android phones, older Nokia and Samsung handsets and voice-memo apps use it. Browsers cannot play it, so this page uses ffmpeg.wasm — the open-source FFmpeg engine compiled to WebAssembly, with its built-in AMR-NB and AMR-WB decoders — and then LAME for the MP3. Both run inside your browser tab: your calls stay on your device.
How to use the AMR to MP3 Converter
- Drop your .amr, .awb or .3ga files on the box, or click to choose them. Each one shows whether it is narrowband (8 kHz) or wideband (16 kHz), its bitrate and its length.
- Keep MP3 and the preselected 64 kbps — plenty for a phone call. Choose 128 kbps for wideband (AMR-WB) music or meetings.
- Press Download converter (32 MB) & convert. The converter is fetched once and cached; later files start at once.
- Press Play to check a recording, then Download, or Download all (ZIP) for several.
AMR to MP3 Converter features
AMR-NB and AMR-WB
Narrowband AMR (4.75–12.2 kbit/s, 8 kHz) and wideband AMR-WB (6.6–23.85 kbit/s, 16 kHz) are decoded by FFmpeg’s own decoders.
3GA and 3GP voice files
Recordings wrapped in a 3GP container (.3ga, .3gp) are accepted too. If one turns out to hold AAC instead of AMR, your browser decodes it directly.
Right-sized MP3s
Mono MP3 from 64 kbps — about 0.5 MB per minute — keeps everything a phone call contains.
Batch and ZIP
Convert a day’s or a month’s call recordings in one pass.
Facts before converting
The page counts the AMR frames itself to show the exact length and bitrate before the converter is downloaded.
Private by design
Call recordings are personal: nothing is uploaded, logged or stored.
AMR-NB or AMR-WB: what is in your file?
One minute of 12.2 kbit/s AMR-NB takes about 95 KB, so an hour-long call is only around 5.7 MB. The MP3 will be larger — roughly 0.5 MB per minute at 64 kbps — because MP3 is a general-purpose codec, not a speech codec. It cannot sound better than the AMR it came from: converting makes the recording playable everywhere, not clearer.
| Type | Sample rate | Bitrates | Sound | Typical source |
|---|---|---|---|---|
| AMR-NB (.amr) | 8 kHz | 4.75–12.2 kbit/s | Classic phone-call quality, 300–3,400 Hz | Call recorders, older phones, voice memos |
| AMR-WB (.awb, .amr) | 16 kHz | 6.6–23.85 kbit/s | “HD voice”, up to 7 kHz | VoLTE call recorders, newer dictaphone apps |
| 3GA / 3GP | 8 or 16 kHz | as above | AMR inside an MP4-style container | Samsung and other Android recorders |
Making a call recording easier to hear
- Quiet caller? Raise the level of the MP3 with the Audio Volume Booster, which uses a limiter so it does not distort.
- Line hiss or background hum? Try the Audio Noise Remover on the converted file.
- Need the words, not the sound? Feed the MP3 to Audio to Text for an offline transcript.
- Recording laws differ by country and state. Make sure you are allowed to keep and share a call before sending it on.
How it works
An AMR file is a six-byte #!AMR header (nine bytes, #!AMR-WB, for wideband) followed by 20-millisecond frames, each starting with a byte that gives its mode. The page walks these frames to measure the length. FFmpeg’s amrnb or amrwb decoder then produces 16-bit PCM, which LAME encodes as a constant-bitrate MP3 after resampling to 48 kHz, one of the sample rates the encoder here works at. Multichannel AMR (#!AMR_MC1.0), a rare variant FFmpeg does not decode, is refused with an explanation.
AMR to MP3 Converter FAQ
How do I convert AMR to MP3 online for free?
Drop the .amr file here, keep MP3 at 64 kbps, press Download converter (32 MB) & convert, then Download. No account or upload is needed.
Are my call recordings uploaded anywhere?
No. The file is decoded and encoded inside your browser. Only the converter program is downloaded, from a public CDN.
Why can’t my computer play AMR files?
AMR was designed for mobile phone networks, and most browsers and desktop players do not include a decoder for it. MP3 plays everywhere.
Will converting improve the sound quality?
No. AMR keeps only what a phone call needs, roughly 300–3,400 Hz for narrowband. The MP3 sounds the same, just in a format everything can play.
What about .3ga files from a Samsung phone?
They are accepted. Most hold AMR and go through FFmpeg; if one holds AAC, your browser decodes it directly.
Which bitrate should I choose?
64 kbps mono is plenty for narrowband calls. Use 96–128 kbps for wideband (AMR-WB) recordings.
Can I convert many recordings at once?
Yes. Add as many files as you like, convert them together and press Download all (ZIP).