MIDI CONVERTER · WHICH DIRECTION DO YOU NEED?
MIDI Converter: MP3 to MIDI, or MIDI to MP3?
“MIDI converter” means two different jobs. To turn an MP3 or other audio file into a MIDI file of notes, use the free MP3 to MIDI converter on this site: it runs in your browser and does not upload your audio. To turn a MIDI file into an MP3, you need a synth or DAW to play the notes with an instrument sound and record the result—this site does not do that direction.
The two directions at a glance
| You have | You want | What has to happen | Where |
|---|---|---|---|
| MP3, WAV, M4A, FLAC, OGG, AAC or WMA | A .mid file of notes | Note detection: a model listens to the audio and writes the pitches and timings it finds | This site’s converter, in your browser |
| A .mid file | An MP3 you can play anywhere | Rendering: an instrument (software synth or sample library) plays the notes and the output is recorded and encoded | A DAW, notation app or MIDI player that can export audio |
The first direction is guesswork done by a model and is never guaranteed note-perfect. The second direction is playback: it reproduces exactly the notes in the file, but how it sounds depends entirely on the instrument you pick.
Our round-trip test: audio → MIDI → MP3
To show what survives a trip through MIDI, we reused the four-note test melody (C4, E4, G4, C5) from our WAV vs MP3 test. That four-second WAV had been converted with this site’s live converter, which returned a 72-byte MIDI file with four notes.
We then rendered those four MIDI notes back to audio with a plain sine-wave synth (each note at the pitch, start time, length and velocity stored in the MIDI), and encoded the result as a 64 kbps MP3.
| Step | File | Size | What it contains |
|---|---|---|---|
| 1. Original audio | melody.wav | 352,844 bytes | 4 seconds of recorded samples |
| 2. Audio → MIDI (this site) | source-from-wav.mid | 72 bytes | 4 note events: MIDI 60, 64, 67, 72 |
| 3. MIDI → MP3 (sine synth) | rendered-sine.mp3 | 32,643 bytes | About 4.05 seconds of new audio playing those 4 notes |
What carried through: the four pitches and their start times and lengths, because those are what MIDI stores. What did not: anything about the original sound itself. The rendered MP3 sounds like whatever instrument renders it—here a bare sine tone; in a DAW it could be a piano, strings or a synth pad. A MIDI file has no audio to give back.
Inspect the files: original WAV · MIDI from this site · MP3 rendered from that MIDI · parsed note events.
This is one short synthetic melody. It demonstrates what each format stores; it is not an accuracy benchmark for real songs.
How to convert MP3 to MIDI here
- Open the converter. Nothing to install, no account.
- Choose one audio file. MP3, WAV, M4A, FLAC, OGG, AAC or WMA, up to 50 MB and 3 minutes.
- Convert and keep the tab open. The model runs on your device; your file is not uploaded.
- Download the .mid file and open it in a DAW or MIDI editor to fix notes and pick a sound. What is in your MIDI download? explains what to expect.
How to turn a MIDI file into an MP3
- Open the .mid file in a DAW or notation program that can export audio.
- Assign an instrument to the track. Without one, there is nothing to hear.
- Export (bounce) the track as WAV or MP3. If your program only exports WAV, encode that WAV to MP3 afterward.
If your MIDI came from this site, it holds detected notes on one track. Clean up stray or missing notes before rendering, otherwise the mistakes are rendered too. See extra chord notes and first note starts late for common fixes.
Which converter for which source?
The same audio-to-MIDI converter handles every supported format, but sources behave differently. For specific tips see WAV to MIDI, piano to MIDI, voice to MIDI and guitar to MIDI. Full mixes with drums and several instruments are not separated into tracks.
Questions
Can this site convert MIDI to MP3?
No. This site converts audio (MP3, WAV and other formats) to MIDI. To make an MP3 from a MIDI file, open the MIDI in a DAW or synth, choose an instrument sound, and export or bounce the audio.
Will converting MP3 to MIDI and back give me my original MP3?
No. MIDI keeps detected notes and timing, not the recorded sound. In our test, a 4-note MIDI file rendered back to audio contained the same four pitches, but the sound came from the synth we chose, not from the original recording.
Why is a MIDI file so much smaller than an MP3?
MIDI stores note instructions instead of audio samples. In our test the four-note MIDI was 72 bytes, while the four-second MP3 rendered from it was 32,643 bytes.
Is my audio uploaded when I convert MP3 to MIDI here?
No. Decoding and note detection run in your browser. The site only delivers the converter, model and decoder files.