Drop an audio file or record from your microphone, and download a standard .mid file. Runs in your browser - nothing is uploaded, and there is nothing to sign up for.
It listens to one pitch at a time. For every slice of audio it estimates a single fundamental frequency, then turns a run of stable pitch into one MIDI note. That is the whole method, and it sets both the strengths and the limits below.
These are limits of the method, not settings you can tune past. Where a commercial service offers chord recognition, instrument separation or one MIDI track per instrument, it is running a trained model - that is not something this page does or claims to do.
Everything happens on your device, in this order.
decodeAudioData). Formats the browser cannot decode are reported back to you by name.Sensitivity sets the YIN threshold: lower keeps more notes but trusts noisy frames more, higher demands a cleaner periodic signal. The shortest-note control removes the flutter that otherwise shows up as a spray of very short notes.
Whatever your own browser can decode - in practice WAV, MP3, OGG, M4A and AAC, FLAC, and WebM or Opus on current Chrome, Edge, Firefox and Safari. This page uses the browser's own decoder, so the list is your browser's, not ours. Formats such as WMA are usually rejected by browsers; when a file cannot be decoded this page says so instead of failing quietly.
No. There is no account, no sign-up and no log-in. The convert button works on the first visit.
No. The file is decoded and analysed by JavaScript on your own device. Nothing is sent anywhere and there is no backend.
Yes - both are ordinary browser-decodable formats, so they go through the same path as anything else. WAV is uncompressed and tends to give slightly cleaner detection than a low-bitrate MP3.
Usable on a clear monophonic line, unreliable on a dense mix. See the section above for exactly which material works and which does not, and expect to clean up a few notes in your DAW either way.
Files above 80 MB are rejected before decoding, because the browser has to hold the whole decoded track in memory. Analysis time grows roughly linearly with length; the page shows you how long it took and how many notes came out. In a test in Chrome on this machine, 60 seconds of WAV took 1.8 seconds to analyse.
A standard MIDI file, format 0, one track, 480 ticks per quarter note, with a tempo event set to your BPM. Each detected note is a note-on and note-off pair, with velocity taken from that note's loudness.
No. This page reads a local file or your microphone only. It does not fetch remote media and does not demux video, so there is no such button.
No. This page handles one file at a time, and there is no batch mode.