AudioMIDI

You drop in a recording, and AudioMIDI estimates the notes. The result is MIDI, the performance instructions a DAW reads: which pitch, when it starts, how long it lasts and how hard it was played. Before downloading, you can watch the decoding and detection stages, check the notes in a piano roll, and choose a playback instrument in the Studio to hear the phrase back. A built-in example lets you listen to an eight-second piano phrase and follow its sixteen note events.

Quick mode is the default. It runs in your browser with no sign-in and doesn't upload the file. It accepts MP3, WAV, OGG, FLAC and M4A, up to five minutes and 25 MB, whichever limit you hit first. The page spells out what that means in practice: a CD-quality stereo WAV reaches the size cap at about two and a half minutes.

The site is unusually frank about accuracy. It suggests starting with one clear piano, guitar or sung melody, and warns that doubled vocals, percussion, reverb and instruments in the same register lead to extra or missing notes. It also points out that converting an MP3 to WAV first won't recover detail the compression already threw away, and that changing the playback sound doesn't rerun the transcription. The expectation is that you fix octave errors and stray notes in your own music software afterwards.

For tougher material there's Deep mode, a separate server-assisted path. You have to confirm permission and upload consent and pass a verification check before the file leaves your machine.

The privacy policy, dated October 31, 2026, says Quick mode keeps the recording on your device. Deep mode sends it through a Cloudflare Worker to a transcription service on Modal, using temporary files that are removed when processing ends, and there's no online library of uploads. The site keeps an anonymous browser ID and your instrument preferences in local storage, and uses Upstash and Cloudflare for quota records that don't include audio. The policy also says advertising is planned but not yet enabled. It doesn't name a person or company behind the site beyond the Audiomidi.app name and a contact address.