Convert a local piano recording into one downloadable MIDI note track. Free, no sign-up. Accepts MP3, WAV, M4A, FLAC and OGG up to 100 MB or 10 minutes. Two CC0 piano recordings we ran through this page produced 521 and 563 notes in a single track.
Conversion runs entirely in your browser. Your audio is not uploaded to any server.
On October 26, 2026, we selected two CC0 piano recordings in the live browser converter, downloaded each .mid file and read the downloads with an independent MIDI parser. Both results contain one note-bearing track. These are output counts from one Windows computer, not accuracy scores or speed promises.
Every detected pitch in both results sits inside the 88-key range of MIDI 21 to 108; no output note falls outside the instrument. Neither recording has an aligned score, so the short notes and any extra pitches are items to inspect, not confirmed errors, and we publish no accuracy percentage for piano input.
The first second of the piano-loop.wav result contains a note at MIDI pitch 45 (A2, 110 Hz) that the converter wrote as six separate notes, each starting exactly where the previous one ends: onsets at 0.0115, 0.1042, 0.1740, 0.2437, 0.3135 and 0.4531 seconds, the last one ending at 0.8823 seconds. Opened in a MIDI editor, that reads as six presses of the same key.
We measured the recording instead of assuming either answer. A short-time magnitude envelope at 110 Hz across the same span shows one attack, at 0.02 seconds, and no second attack. The level stays above 26% of its peak from 0.02 to 0.90 seconds and never returns to the noise floor. The recording holds a single sustained A2 there.
The six notes are therefore a split of one sustained tone, not six key presses. Nothing in the audio marks the five boundaries at 0.1042, 0.1740, 0.2437, 0.3135 and 0.4531 seconds. This is what a piano pedal note looks like after conversion: the pitch is right and the note count is wrong.
A seventh note begins at 0.8823 seconds, exactly where the sixth ends, and this one is a genuine second strike: the 110 Hz level reaches its lowest point in the span, 26% of peak, at 0.88 seconds, and a new attack follows. So the split runs from 0.0115 to 0.8823 seconds, and the strike after it is real.
What would settle it: a piano recording with a published score and one sustained note at a known time, so every output note can be matched against a written one. Neither clip here has that reference. The envelope check above needs only the source WAV and can be repeated on any recording without the model.
Choose a local piano recording above and convert it. The audio is decoded in your browser, resampled to 22,050 Hz mono and passed to the note-detection model. Whatever the model reads as a note becomes one MIDI note in one track.
Practical limits for piano: a chord is written as simultaneous notes rather than separate hands or voices; a sustained pedal tone can be split into several notes as shown above; the file carries no pedal, hand, fingering or dynamics markings beyond a single velocity per note; and any singing, room noise or backing track in the same file is merged into the same track. This tool does not separate instruments and does not produce sheet music.
Open the downloaded .mid in a MIDI editor and compare it with your recording before using it in a project. A repeated run of short notes on one pitch is the first thing to check, because it may be one held note. For the same converter on other inputs, see the MP3 measurements, WAV scale test, voice test, guitar test and whole-song test.