AMR to MP3, rescued from 2009.
AMR is the sound of old phones: Nokia memos, early Android call recordings, MMS voice clips. No browser and almost no modern player decodes it. This page does — with a WebAssembly ffmpeg engine that runs on your device, so a possibly-private old recording still never gets uploaded.
Add your files
Drag files here, or press the button. Any common audio works — and videos too: we take just the sound out of an MP4 or MOV. Your files stay on your device the whole time.
MP3 · M4A · WAV · FLAC · Ogg · Opus · MP4 · MOV — even old AMR and WMA files. You can also paste a file from the clipboard.
Pick the format you want
Not sure? MP3 is the safe answer — it plays on everything.
Advanced options — quality, mono/stereo, volume+
The defaults are good — you can skip this whole box.
Higher = better sound, bigger file.
Mono halves the size — fine for voice.
Your privacy — live proof, not a promise
- Files uploaded
- 0 bytes
- Processing
- Not started yet
- Your files
- Stay in this browser tab — gone when it closes
- Converter engine
- Not downloaded — only fetched if a format needs it
One download, and it isn’t your audio
Converting to MP3 or WAV needs no download at all. Less common formats use a built-in converter engine (32.5 MB) that comes from this site — not from some other company — downloads once, and is then saved in your browser. Your audio is never part of that download: the engine comes to your files, your files don’t go to it.
Don’t take our word for it: open your browser’s DevTools, watch the Network tab, then convert a file. You’ll see nothing carrying your audio — because this page has no upload feature at all. There is nowhere for your file to go.
Scope note, so this stays exact: the claim is about your files — they never leave this device. The site around it is not claim-free. It loads Vercel Analytics for aggregate page traffic, plus Google Analytics and Ads tags if you accept the consent prompt. Those measure page visits and store-link clicks. They never receive your audio, because nothing does. Full privacy policy.
Converted files are never stored by this page — they exist only in this tab until you download them.
Shrinking, not just converting?
If the point is a smaller file — an attachment cap, a full phone — the free audio compressor solves backwards from a target size and lets you A/B the quality before you commit.
Convert, then transcribe
Need the words, not the audio? The free audio to text tool transcribes the same files on your device — no conversion step needed for anything a browser can decode. Or capture something new with the free online voice recorder.
Why nothing plays AMR any more
AMR is a telephone-network codec — designed to squeeze a voice down GSM's 12.2 kbps channel, adopted by phone makers for memos because the chip already spoke it. It was never a music format, browsers never shipped it, and when phones moved to AAC the ecosystem forgot it. The recordings are fine; the players left.
How this page decodes what browsers can't
The fast conversion path on this site uses the browser's own decoder, which refuses AMR. So this conversion loads the fallback engine: ffmpeg compiled to WebAssembly, fetched once (~32 MB, served from this site, cached in your browser), running entirely locally. The page labels which engine handled each file — for AMR it will say ffmpeg, and the Network tab will still show zero uploads.
Set expectations for the audio itself
AMR recorded sound the way an old phone call sounds — tinny and narrow — and the MP3 will sound exactly the same, because that is all the file ever contained. The default settings keep everything AMR has. What you gain is not fidelity but a future: an MP3 plays on everything, and will keep playing on everything.
How the conversion works
The same four steps whatever you drop in — none of them involve a server. The free online audio converter hub explains the whole pipeline, the format chooser and the comparison with upload-based converters.
Your browser opens the file itself
Drop a file in, and your browser reads it with the same built-in player it uses to play sound on any website. Videos work too — we take just the sound out of an MP4 or MOV and leave the picture alone. At this point nothing has left your device, and nothing will.
Your device does the converting
For MP3 and WAV, a small converter runs right here in this tab. For less common formats — Opus, Ogg, FLAC, M4A, or old files like AMR and WMA — a bigger converter engine (ffmpeg, ~32 MB) downloads once from this site and then also runs on your device. Either way, the work happens on your computer or phone, not on a server.
Trim and tidy before converting
You can cut silence off the start and end, make the sound louder, and choose the quality — all before the file is converted, so it is only converted once. Hidden info inside the file (like when and where it was recorded) is removed automatically, because a file you are about to share should not quietly carry that.
Download straight from this tab
The finished file is built in this tab and handed to you as a normal download — one at a time, or a whole batch bundled into a single ZIP. Close the tab and everything in it is gone. There is no account and no cloud copy, because there is no cloud.
AMR to MP3 — questions, answered
Why can't my phone or browser play AMR files directly?+
AMR was a mobile-network voice codec, not a consumer format. Modern platforms dropped it years ago, so files from old phones stopped opening anywhere. Converting to MP3 moves the audio into a format that has never stopped being supported.
Is the AMR file uploaded for conversion?+
No. AMR needs the ffmpeg engine, and that engine runs as WebAssembly inside your browser. What downloads is the engine itself, once, from this site — your recording stays on your device throughout, which matters because old AMR files are often calls and personal memos.
Will converting improve how the old recording sounds?+
No — AMR recorded at telephone bandwidth, and no format change adds frequencies that were never captured. The MP3 will sound the same and play everywhere. Convert at 64 kbps mono; more buys nothing for this source.
Is this audio converter really free, with no limits?+
Yes. No account, no daily limit, no file-size tier and no watermark. Your own device does the converting, so an extra file costs us nothing — there is simply nothing for us to charge for or to cap.
Is my audio uploaded anywhere?+
No. The file is opened and converted inside your browser, on your device. This feature has no upload button behind the scenes — there is nowhere for your audio to go. Want proof? Open your browser's DevTools, watch the Network tab while you convert, and you'll see nothing carrying your audio.
What is the maximum file size?+
We don't set one. The real limit is your device's memory, because the whole file is handled in this tab. Files over 2 GB are refused, and if a file looks heavy for your device, the page warns you before starting. A laptop handles multi-hour recordings; a phone prefers shorter ones.
Does it work offline?+
Converting to MP3 or WAV works offline once the page is open. Other formats (Opus, Ogg, FLAC, M4A) need the bigger converter engine, which downloads once (~32 MB) from this site — after that it's saved in your browser, so those conversions work without re-downloading too.
Can I convert video files to audio?+
Yes. Drop in an MP4, MOV or WebM video and you get just the sound out of it — that's the whole 'MP4 to MP3' trick. The video itself is never uploaded or changed; only its audio is read.
Why is there no 'paste a link' option?+
Because this tool is for your files, from your device. A link box would turn it into a tool for downloading other people's audio from around the web, which is not what it's for — and every link would send someone's listening history through a converter. Local files only, on purpose.
What does 'remove hidden info' actually remove?+
Details stored invisibly inside the file: title, artist, album art, the exact time it was recorded, which app or phone recorded it, and sometimes even GPS location. It's removed by default because a file you're about to share shouldn't quietly tell people all that. Turn the option off and the details are kept instead.
Other conversions
Files worth converting start as recordings.
BlackBox records your day straight to compact, transcribed, searchable files on your phone — nothing to convert afterwards. Free on iPhone and Android.