MIDI to MP3

Method

How to Convert MIDI to MP3

1. Drop one or several .mid or .midi files onto the tool above
2. Each file is parsed and its notes performed by the built-in synth, on your device
3. The result is normalised so nothing clips, then encoded
4. Download the MP3, or the WAV if it is going straight into a DAW

Why MIDI Has No Sound of Its Own

This is the single fact that explains every confusing thing about MIDI. The file is a score: note 60 starts at 1.2 seconds, lasts half a second, played this hard, on channel 3 with program 0. It contains no audio at all, which is why a two-minute orchestral arrangement can be 12 KB, and why the same file sounds like a grand piano in one program and a cheap keyboard in another. The sound always comes from whatever performs it. That is also why a converter has to make a choice on your behalf, and why an honest one tells you which choice it made.

What This Renderer Does and Does Not Do

It reads every track, keeps the tempo map, the note timing and the velocities, and performs them with a small synth whose timbre is chosen per General MIDI family: a plucked tone for pianos and guitars, a bowed one for strings and pads, a short noise burst for the drum channel. The mix is then normalised to just under full scale so a dense arrangement does not clip. What it does not do is reproduce specific instruments, because that needs a soundfont measured in megabytes. If the file is a melody, a bassline, a drum pattern or a sketch you want to hear away from the DAW, this is enough. If it is a full orchestral arrangement you need to sound real, render it in a DAW instead and use this to check it in the meantime.

The Other Direction

Going from audio back to notes is the harder problem and a separate tool: the audio to MIDI converter transcribes a melody out of an MP3 with a neural model. The pair covers the round trip, which is how most people actually work: transcribe a line you like, edit the MIDI, then render it back to audio here.

Frequently Asked Questions