MP3 to MIDI Converter

Transcribe any MP3 to a playable MIDI file — free, in your browser. Choose full mix, 2-track, or 4-track stem separation. Nothing is ever uploaded.

🔒 No upload ⚡ Instant ✓ Free 🎹 3 modes

Three conversion modes

Filesmith offers three ways to convert your MP3 to MIDI, depending on how much detail you need:

MODE A

Full Mix

Whole audio → 1 MIDI track. Best for solo instruments or simple melodies.

MODE B

2 Tracks

Splits melody from drums using harmonic-percussive signal processing.

MODE C

4 Tracks

Separates drums, bass, melody, and other into 4 individual MIDI tracks.

How it works

Most online audio-to-MIDI tools upload your file to a server, process it, and send it back. Filesmith is different — everything runs locally in your browser using the Web Audio API and JavaScript signal processing. Your MP3 is never sent anywhere.

Pitch detection uses a YIN algorithm with FFT-based autocorrelation. Stem separation uses HPSS (Harmonic-Percussive Source Separation) — a well-established technique that splits audio into harmonic content (melody, bass) and percussive content (drums, transients) using spectral median filtering.

What makes a good result?

Solo or simple recordings — a single instrument or voice converts with the best accuracy.
Clear pitch — recordings with minimal reverb or distortion transcribe more cleanly.
Distinct beat — for Mode B and C, tracks with a clear rhythm produce better drum separation.
Shorter files — Mode C takes longer on long files. For best speed, trim to the section you need.

What can I do with the MIDI file?

The downloaded .mid file opens in any DAW — FL Studio, Ableton Live, GarageBand, Logic Pro, Reaper, and more. You can use it to identify chords, rearrange a melody, practice a song, or build a new production from the transcribed notes. MIDI and MID are the same format — either extension works.

Also accepts WAV, OGG, FLAC

The tool accepts any common audio format — not just MP3. Drop a WAV, OGG, FLAC, M4A, or AAC file and it works exactly the same way.

MIDI isn't audio

This is the thing worth understanding before you start, because it explains both what the conversion can do and where it falls short. A MIDI file contains no sound at all. It stores instructions — which note, when it started, how long it lasted, how hard it was struck — and something else turns those instructions back into sound.

So this conversion isn't changing a file's format the way MP3 to WAV does. It's listening to a recording and writing down the notes. That's why the result depends so heavily on what you feed it, and why a solo line transcribes far better than a full mix.

What people use it for

Transcribing a melody you recorded or found, without working it out by ear
Pulling a bassline or chord progression into a DAW to replay with any instrument
Fixing the timing or pitch of a performance after the fact
Building a new arrangement from the notes of an existing one
Learning a part by seeing it laid out in a piano roll instead of hunting for it

It used to take expensive software or handing your audio to someone else's server. Running it in the browser means neither.

Frequently asked

Will the MIDI sound the same as the MP3?

No — MIDI is not an audio recording. It's a sequence of note instructions that get played back by a software instrument or synthesizer. The MIDI captures the notes and timing from the MP3, but the actual sound depends entirely on what plays it back.

What's the difference between Mode A, B, and C?

Mode A converts the entire mix into a single MIDI track — best for solo instruments. Mode B splits melody from drums into two tracks. Mode C separates drums, bass, melody, and other into four tracks for more detailed editing.

Why is the result imperfect?

Audio-to-MIDI conversion is fundamentally hard — the software has to identify individual notes from a complex audio waveform. Solo instruments and clean recordings produce the best results; full mixes with reverb and effects are much harder.