New in the kilnstl → gcodepsd → pngpdf → csva/b significanceutm builder
MP3 to MIDI Converter
Convert MP3, WAV, or OGG audio to a MIDI file using Spotify's open-source Basic Pitch model, running entirely in your browser. Audio never uploaded.
Private by construction. Your file is opened with JavaScript inside this page. It is never transmitted, and the tool keeps working with the network unplugged.
Drop in a recording and get a MIDI file of the notes it contains, transcribed by Basic Pitch — the open-source neural network Spotify's audio research team published — running entirely inside this page. Your audio is decoded, resampled, and fed through the model locally; the ~1 MB model downloads once and nothing you play ever leaves the machine. The result renders as a piano roll so you can see what was heard before downloading, with note velocities taken from the model's confidence and pitch bends preserved. Honest expectations: transcription is an estimation problem. Solo piano, guitar, voice, and other clearly pitched sources come out remarkably well; dense mixes with drums come out impressionistic.
Questions this tool gets asked
Is my audio uploaded for processing?
No. The neural network runs in your browser via TensorFlow.js. After the page and the ~1 MB model load, you can disconnect from the internet and transcription still works.
What model does the transcription use?
Basic Pitch, published as open source by Spotify's Audio Intelligence Lab and described in their ICASSP 2022 paper. It detects note onsets, pitches, and pitch bends, and supports polyphony - chords transcribe, not just single melodies.
Why doesn't my MIDI sound exactly like the recording?
MIDI stores notes, not sound. The synthesizer or instrument you load the file into supplies the timbre. And transcription itself is probabilistic: quiet notes, heavy reverb, distortion, and drums all reduce accuracy - every audio-to-MIDI tool shares this, including the paid ones.
What audio formats work?
Anything your browser can decode: MP3, WAV, OGG, FLAC, and M4A/AAC in current browsers. Length is limited only by memory and patience - a 3-4 minute song transcribes in well under a minute on a modern laptop.
What tempo does the MIDI file use?
The file is written at 120 bpm with note timings in real seconds, so it plays back at the recording's true speed in any DAW. Beat-mapping to bars is a musical judgment this tool leaves to you.