How do I convert an MP3 to MIDI?

Drop the MP3 (or a WAV, M4A, OGG or FLAC file) above and press Convert to MIDI. The notes appear in a piano roll that you can play back; adjust the sensitivity if notes are missing or extra, then press Download MIDI to save a .mid file you can open in any DAW, notation program or MIDI keyboard app.

Does it work for piano, guitar and voice?

Yes. The Basic Pitch model was trained on many instruments, including piano, guitar, strings, wind and singing. Solo piano and guitar give the cleanest results. For a voice, humming or a lead instrument, turn on Melody only so you get one clean line. You can also record yourself with the microphone button.

Is it polyphonic? Can it detect chords?

Yes. It detects several notes at the same time, so chords and accompaniment come through, not just the melody. It does not separate instruments: everything goes into one MIDI track, and drums are not transcribed. With a full band mix, expect extra notes; Melody only or the sensitivity sliders help.

Is my audio uploaded anywhere?

No. The audio is decoded and transcribed in your browser, and the MIDI file is written on your device. The only download is the 230 KB note model and the engine that runs it, fetched once from our own server and then cached. It is free, with no sign-up.

Why does the MIDI not match my song's tempo?

The notes are placed at their real times, written at 120 BPM, so the file plays back exactly like the recording. The song's own tempo is not detected. To line the notes up with bars in a DAW, set the project to 120 BPM, or find the tempo with the BPM & Key Finder and adjust it there.

Yes. Every tool is free to use, with no account and no credit card. The work runs on your device rather than on our servers, which is what keeps it free to run.

Are my files uploaded?

No. Your files are opened and processed inside your browser and are not sent to LibraTool. Some tools first download a processing engine or AI model to your browser; that download contains no data of yours.

Does it work on mobile?

Yes. It runs in current mobile browsers on iOS and Android, with nothing to install. Very large files can be slow or run out of memory on a phone, so use a computer for those.

🎹

Free Audio to MIDI Converter

Convert MP3, WAV or a recording of piano, guitar or voice into a MIDI file. Detects chords and melodies on your device; nothing is uploaded.

File size depends on your deviceFiles stay privateNo login requiredFree foreverOne-time 26 MB download (AI model and engine)Runs on your devicePolyphonic · .mid

Turn a recording of piano, guitar, voice or any instrument into MIDI notes you can edit in a DAW. Notes are found by Spotify's Basic Pitch model, running in your browser.

Drop a file here, or click to browse

MP3, WAV, M4A, AAC, OGG, FLAC, WEBM, OPUS, MP4, MOV · processed on your device

or press Ctrl+V to paste from your clipboard

Browse files

Or hum, sing or play into your microphone (up to 60 seconds).

Your files never leave your device. All processing happens locally in your browser.

Works best with one instrument or voice. In a full mix with drums, expect extra notes: try Melody only, or remove the vocals or noise first.

Note detection: Basic Pitch by Spotify (Apache-2.0).

How It Works

Turn a recording into MIDI notes. The notes are found by Basic Pitch, an open-source note-transcription model from Spotify, run in your browser. It hears several notes at once, so chords come through as well as melodies.

1
Audio is read locally
Your file or microphone recording is decoded on your device and converted to the format the model was trained on.
2
The model listens
Basic Pitch estimates, for every piano key and every few milliseconds, whether a note is sounding and whether one is starting. The 230 KB model downloads once and is cached.
3
Notes are picked out
Note starts above your sensitivity begin a note, short notes are dropped, and Melody only keeps the highest note at each moment. Moving a slider updates the notes instantly.
4
Preview and download
Check the piano roll, play the notes, and save a standard .mid file for any DAW, notation app or keyboard.

Your audio never leaves your device. Only the note model is downloaded, once.

Guide

Worked example

A 2-minute solo piano recording saved as a 192 kbps MP3 of about 3 MB. After you press "Convert to MIDI", it is decoded, then analysed in short overlapping windows of about 1.6 seconds each, so you will see "part" counts in the dozens. The tool writes a one-track .mid file with the notes at their real times, at 120 BPM, and shows them in a piano roll with a summary of the note count and range. A clean piano take often needs no changes, and a few seconds of noise or a quiet room tone may add stray notes that a higher "Shortest note" setting removes.

Which settings to use, and the limits

Start with one instrument or one voice. The model is built for one instrument at a time. A full mix gives extra and wrong notes. If you can, convert a stem or a recording without drums or backing vocals.
Adjust the sliders after converting. "Note sensitivity" controls how quiet a note can be. "Note-start sensitivity" controls how readily fast repeated notes are split. "Shortest note" (30 to 500 ms) drops anything shorter. Changes apply to the notes right away, with no need to convert again. "Reset to defaults" brings back the starting values.
Turn on "Melody only" for a single line. It keeps the highest note at each moment and drops chords under it. Use it for a voice, humming or a lead instrument. Leave it off for piano chords.
Know the length and recording limits. The first 10 minutes of a file are converted. A file longer than 20 minutes is refused, so cut the part you need with the Audio Trimmer. The microphone records up to 60 seconds. A file over this device's size limit is also refused.
Set your DAW to 120 BPM. The notes sit at their real times in a file written at 120 BPM, but the song's own tempo is not detected. To line notes up with bars, set the project to 120 BPM or adjust tempo in the DAW.

Common problems and how to fix them

It says the file could not be read as audio.: The input must be audio such as MP3, WAV, M4A, OGG or FLAC. A MIDI file (.mid) or a phone ringtone format will not decode. If the format is unusual, convert it to MP3 or WAV first.
The file changed or moved after you picked it.: The file was probably in cloud storage or still copying. Copy it to a local folder and choose it again.
No notes were found.: Raise "Note sensitivity", or use a recording with less background noise. Audio that is only a fraction of a second long is also rejected.
The note model could not be loaded.: The small model (230 KB) did not download. Check your connection, reload the page and try again.
Too many extra notes appear.: Lower "Note sensitivity", raise "Shortest note", or try "Melody only". Background music, reverb and drums add notes the model cannot tell apart from the main part.

How it compares

MIDI describes which notes were played and when, not how they sounded. That is why a MIDI file is tiny and can drive any instrument in your DAW, but the conversion from audio is an estimate that can miss notes or add some. Treat the result as a draft to tidy in an editor, not as a perfect score.

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