Why voice notes won't play anywhere
WhatsApp saves voice messages as .opus, iPhone voice memos are .m4a, and voicemail systems email you .caf or .amr files. Each plays fine in its home app and fails in car stereos, editing software, transcription tools, and court/HR submissions. MP3 plays everywhere — that's the fix.
Privacy isn't optional here
People convert voice notes for serious reasons: saving a loved one's messages, evidence for a dispute, an interview recording. Every other converter makes you upload the audio first. Here, decoding and MP3 encoding both happen in your browser's memory — airplane mode works, and there is no server copy because there is no server.
FAQ
How do I get the .opus file out of WhatsApp?
On a phone: open the chat → tap-and-hold the voice note → share/export. On WhatsApp Web/Desktop: the download arrow saves the .opus directly. Then drop it here.
Can I convert many at once?
Yes — drop the whole folder. Flip Auto-download and you get one zip back with every MP3.
What about .amr voicemails?
Browser decoders mostly don't speak AMR yet — that one's on our workbench. Everything else on this page works today, and Safari can be picky with .opus (Chrome and Firefox handle it).