MP3 to MIDI

Result

Supported inputs

Any audio file your browser can decode. In current desktop and mobile browsers that typically includes MP3, WAV, OGG, M4A / AAC and FLAC. If the browser cannot decode the file, this page will say so instead of guessing.

Output: a Standard MIDI File (SMF) format 0, single track, 480 ticks per quarter note, 120 BPM. The file contains the detected melody line only.

How the conversion works

1. Your file is decoded into raw audio samples in the browser (Web Audio API). Nothing is uploaded.
2. The audio is read in short overlapping frames. Each frame is analysed for a fundamental pitch using a YIN-style pitch detector.
3. Consecutive frames holding the same pitch are grouped into a note, with a minimum length so that flicker does not become a note.
4. Each note is written as a MIDI note-on / note-off pair and packed into a Standard MIDI File.

Because every step happens in your browser, the audio never leaves your device. There is no server, no account, and no upload.

What this does and does not do

It extracts a single melodic line. This page runs a monophonic pitch detector: it tracks one pitch at a time. Clean, single-line sources — a vocal, a flute, a synth lead, a solo instrument — give the most usable MIDI.

It is not a full multi-instrument transcription. For dense, polyphonic material (a full band mix, piano with chords, several instruments at once), a monophonic detector has to pick one line to follow, so the output is an approximation of the top melody rather than every part notated. Complex chords are not separated into individual voices.

Accuracy depends on the source. Solo recordings in a quiet environment work well; heavily compressed, reverberant, or very noisy audio gives a rougher result. No accuracy percentage is claimed here, because the honest answer is that it varies with the recording.

Privacy

The file you choose is read locally by your browser and is not sent anywhere. This page makes no network requests with your audio.

FAQ

Is this an MP3 to MIDI converter?

Yes. You give it audio, it returns a MIDI file. The same page also covers the other ways people phrase this task — you can change MP3 to MIDI, convert an MP3 file to MIDI, or convert MP3 into MIDI here; they are the same job and this one tool does it.

Do I need to upload my file?

No. Decoding and pitch detection both run in your browser, so the audio stays on your device.

How do I convert an MP3 file to MIDI?

Drop the file on the box above (or click to choose it), press Convert to MIDI, then press Download .mid. Long files take longer to analyse because every frame is processed on your device.

What can I open the MIDI file with?

Any DAW or notation program that imports Standard MIDI Files — Ableton, Logic, FL Studio, GarageBand, MuseScore, and others. The result is a plain MIDI melody track you can edit, re-instrument, or quantise.

Why does a busy song not come out right?

A monophonic detector follows one pitch at a time. When many instruments play together there is no single pitch to follow, so the output follows the most prominent line and drops the rest. For full arrangements you need a polyphonic transcription service, which requires server-side processing and is not what this page does.