Piano to MIDI: the pitches hold up, the rhythm does not.
Yes, you can convert a piano recording into editable MIDI notes, and the harmony survives. On five seconds of a real public-domain piano recording, 28 of the 30 exported events landed on the chord the passage is built from. What did not survive is the count: that passage holds about 17 sixteenth notes and the export holds 30 events, with lengths from 0.07 to 1.85 seconds for notes of equal written value. Piano is the case where you spend your time thinning a dense export, not hunting for wrong pitches.
Convert your piano audioFive seconds of Bach, and 30 events where there are about 17 notes
The recording is the opening of the Prelude in C major, BWV 846, from Bach's Well-Tempered Clavier, played by Kimiko Ishizaka and released into the public domain as part of the Open Well-Tempered Clavier project. Because the licence is CC0, the audio can be downloaded and compared without restriction. We cut the first five seconds after the music starts and changed nothing else.
This is the hardest kind of piano input: an unbroken run of sixteenth notes with the pedal down, so every attack lands on top of a note that is still decaying. The prelude is 35 bars of continuous sixteenths and this performance runs 162.9 seconds, which puts one note every 0.29 seconds — about 17 notes in five seconds.
The converter returned 30 events. The first ones are correctly spaced at 0.30, 0.27 and 0.23 seconds, matching the sixteenth-note grid; the duplicates appear once several notes ring at the same time and the model reports an extra event between two real ones. Lengths are just as uneven — 0.07 to 1.85 seconds for notes that share one written value.
The pitches are the good news. 28 of the 30 events fall on C, E or G, the chord the passage is built from, spread from C4 to G5; the two outsiders are a D4 and an A4 near the end of the window. Unlike the guitar case there is no octave-doubling layer to delete: dense piano produced too many events, not too many registers.
| Measure | Result |
|---|---|
| Notes in the passage, from the score and the tempo | about 17 |
| Events the converter returned | 30 |
| Events on the passage's chord, C, E and G | 28 of 30 |
| Distinct pitches | 8, from C4 to G5 |
| Note lengths | 0.07 s to 1.85 s for equal written values |
Unlike the guitar and voice cases, there is no note-by-note answer key here: nobody has annotated this performance note by note. The count comes from the score and the tempo, which is enough to say the export is roughly 1.7 times too busy, and not enough to score individual notes as right or wrong.
Four struck notes, one at a time
Before the messy case, the clean one. We made a 4.2-second mono WAV with four separate, struck-string-like tones — C4, E4, G4 and C5, one second apart, each decaying and briefly overlapping the next. This is a computer-generated piano-like signal, not an acoustic performance. It shows what the model does when almost nothing overlaps.
On October 14, 2026, that file went through the public tool. The MIDI contained four events, all with the intended pitch names, starting within a few hundredths of a second of the planned positions.
| Known input | MIDI pitch | MIDI time |
|---|---|---|
| C4, struck at 0.00 s | C4 | 0.00–1.00 s |
| E4, struck at 1.00 s | E4 | 1.00–2.00 s |
| G4, struck at 2.00 s | G4 | 2.00–3.03 s |
| C5, struck at 3.00 s | C5 | 2.99–4.07 s |
Listen to the test input:
From your piano recording to a usable piano roll
- Record a short, clear phrase. Start with a single line and little room echo. If you have a direct digital-piano audio output, it may be easier to inspect than a distant room microphone.
- Convert the audio. Upload the file on the tool page and select Convert to MIDI. The recording is processed in your browser.
- Compare the two timelines. Import the audio and downloaded MIDI into your editor. Check pitches, note starts and lengths. MIDI stores notes, not the original piano sound.
- Clean up the part, deleting first. In a dense passage, remove the events that sit between two real onsets before you touch anything else; then even out note lengths and merge fragments of one held note. Correcting a duplicate is wasted work when deleting it takes a click.
In the dense case above, the work is subtraction: roughly one event in three does not belong to a note that was played, and the fix is to delete rather than to correct. In the four-note case there is nothing to remove at all. Your own recording will sit somewhere between those two, depending on how much rings at once.
M4A, FLAC, AAC and Opus recordings
The same converter handles a supported audio recording regardless of whether it came from a phone or a studio. For M4A to MIDI, select the .m4a file on the tool page; .flac is also listed as an accepted input. The audio codec inside a file still has to decode successfully.
Standalone .aac and .opus files are not currently accepted by the converter. If your piano recording has one of those extensions, export or convert it to WAV first, then use this same piano-to-MIDI workflow. A format change will not repair a noisy or crowded recording.
Piano-to-MIDI questions
Can I convert piano to MIDI without installing piano to MIDI software?
Yes. Midilace runs in a current browser and downloads a standard .mid file. You still need a MIDI editor or DAW if you want to correct or arrange the notes.
Can it read a recording of piano chords?
Yes, and the harmony is the part that holds. On a five-second passage of continuous sixteenth notes, 28 of the 30 exported events were on the passage's own chord. What you will have to fix is the rhythm: the export held about 1.7 times as many events as the passage has notes, and the lengths need evening out.
Does it copy the sound of my piano?
No. The MIDI file contains estimated note events and timing. Your player or instrument plug-in supplies the playback sound.
Will an M4A phone recording work?
The page accepts .m4a files, but decoding depends on the codec in that file. Keep a WAV export as a fallback, and use the clearest recording you have.