Can I convert MIDI to WAV instead of MP3?

Yes. After rendering, choose WAV before you download. You get 16-bit stereo at 44.1 kHz, about 10 MB a minute, which is the better choice if you will edit the audio or put it in a video project. MP3 is smaller and fine for listening and sharing.

Why does my converted MIDI sound different from my other player?

Because a MIDI file only names the instruments; each player supplies its own sounds, and General MIDI does not define what they sound like. This page uses a simple synthesizer, so expect a plainer, more electronic sound than a sample-based player.

Can I use my own SoundFont or sample library?

No. The page has one built-in synthesizer and does not load SF2 or other sound banks. If you need a specific sound, render the file in a music program that supports your library and export the audio there.

Does changing the tempo change the pitch?

No. The tempo slider (50% to 200%) moves the note timings before anything is played, so every note keeps its pitch. That is different from speeding up an MP3, where the audio itself has to be stretched.

Why does my MIDI file not convert?

The most common reasons: the file is not a Standard MIDI File despite its name, it is a rare format 2 file, part of it is damaged, or at the chosen tempo it would run past the 10-minute limit. The page tells you which one it found.

MIDI to MP3 Converter

Turn a MIDI file into an MP3 or a WAV you can play anywhere. The page reads the notes, plays them on a simple built-in synthesizer, lets you change the tempo and hear the result, then saves the audio. Nothing to install.

Drop a MIDI file here, or choose a file

MID, MIDI, KAR or RMI, up to 5 MB. The audio can be up to 10 minutes long.

The sounds are made by a simple synthesizer in this page, one rough voice per General MIDI instrument family plus synthesized drums. Expect a demo-style sound, not the realistic instruments of a DAW or a large sound library.

The file is read and rendered in your browser and is not uploaded.

How to convert MIDI to MP3 or WAV

Three steps; the file stays on your device.

1
Drop the MIDI file
A .mid, .midi, .kar or .rmi file up to 5 MB. The page lists its length, tempo, tracks and General MIDI instruments, so you can check it is the file you meant.
2
Set the tempo and render
Keep 100% or pick anything from 50% to 200%. Because MIDI stores timing, not sound, a faster tempo does not raise the pitch. Rendering builds every note offline, usually faster than the song plays.
3
Listen, then download
Play the rendered audio first. If it sounds right, save it as MP3 (96 to 320 kbps) or as 16-bit WAV for editing. The audio can be up to 10 minutes long.

Already have audio, not MIDI? The Audio Format Converter changes between audio formats, and the WAV to MP3 Converter shrinks a WAV you exported. Need a WAV from an MP3 instead? Use MP3 to WAV.

What is actually inside a MIDI file

A MIDI file holds no sound at all. The MIDI Association puts it plainly: MIDI is not audio, only performance instructions. A Standard MIDI File is those instructions saved with timing, so another device can play them back later. That is why a whole song often fits in a few kilobytes, while the same song as an MP3 takes megabytes.

The instructions are short messages. A note on message names a key (60 is middle C) and a velocity from 1 to 127, which says how hard the key was struck; a note off ends it. A program change picks the instrument. Controller messages carry things like the sustain pedal (controller 64), channel volume (7) and pan (10), and pitch bend slides the pitch up or down.

Time is counted in ticks. The file header says how many ticks make a quarter note, and tempo events say how many microseconds a quarter note lasts; with no tempo event, the format assumes 120 beats per minute. A format 0 file keeps everything in one track; a format 1 file has several tracks that play together, often one per instrument. This converter reads both, follows every tempo change, and lists what it found before you render.

Why the same MIDI file sounds different in every player

General MIDI, first published in 1991, fixed which instrument each program number should be, so a file made on one synthesizer picks a piano on another one too. What it did not fix is the sound. The MIDI Association's own page on General MIDI Level 1 says the acoustic characteristics of each sound are not defined.

So the piano in a phone's built-in player, in a desktop music app and in a sample library are three different recordings or models of a piano, and the file plays on whatever is there. Converting MIDI to MP3 means choosing one of those sound sources and recording its output.

The sound source on this page is a small synthesizer: one rough voice for each of the 16 instrument families and synthesized drums. It keeps the page light and needs no download of sound banks, but it will not sound like a real orchestra. For a realistic result, open the file in a music program with a good sample library and export the audio from there.

The General MIDI instrument families, and how this page plays them

General MIDI lists 128 instruments in 16 families of eight. Tables print the programs as 1 to 128; inside the file they travel as 0 to 127. Channel 10 is kept for drums, where each key is a different drum (keys 35 to 81, 47 sounds).

Programs	Family	Example	Sound on this page
1 to 8	Piano	Acoustic Grand Piano	Bright tone that fades while held
9 to 16	Chromatic Percussion	Vibraphone	Bell-like tone with a short ring
17 to 24	Organ	Church Organ	Steady tone, no fade
25 to 32	Guitar	Acoustic Guitar (nylon)	Plucked tone that fades
33 to 40	Bass	Electric Bass (finger)	Deep plucked tone
41 to 48	Strings	Violin	Bowed tone with vibrato
49 to 56	Ensemble	String Ensemble 1	Slow, wide, layered tone
57 to 64	Brass	Trumpet	Buzzy tone with a quick swell
65 to 72	Reed	Alto Sax	Hollow, reedy tone with vibrato
73 to 80	Pipe	Flute	Soft, near-pure tone with vibrato
81 to 88	Synth Lead	Lead 1 (square)	Hard square-wave tone
89 to 96	Synth Pad	Pad 2 (warm)	Slow, soft, wide tone
97 to 104	Synth Effects	FX 1 (rain)	Wide tone with a long fade
105 to 112	Ethnic	Sitar	Bright plucked tone
113 to 120	Percussive	Steel Drums	Short knock that fades fast
121 to 128	Sound Effects	Applause	Generic buzz, not the named effect

Every instrument in a family shares the family's voice here, so a violin and a cello differ in pitch but not in color. Drums on channel 10 are synthesized: kicks, snares, toms, hi-hats, cymbals and hand percussion each have their own recipe.

What the converter handles, and what it does not

Read from the file
Format 0 and 1 files, tick-based and SMPTE timing, tempo changes, note velocity, program changes, channel 10 drums, the sustain pedal, channel volume, expression, pan and pitch bend, including the bend range a file sets.
Left out
Reverb and chorus settings, bank select (GS and XG variations play as their General MIDI 1 instrument), system exclusive messages and karaoke lyrics. Format 2 files, which store separate patterns, are not played.
Sound quality
A family-level synthesizer, not a sample library or a SoundFont, and you cannot load your own. The finished audio is raised or lowered as a whole so its loudest peak sits at -1 dBFS, which avoids clipping.
Limits
Files up to 5 MB and audio up to 10 minutes at the chosen tempo, because the rendered song is held in your device's memory before it is encoded. Very long or dense files can be slow on a phone.

Notes in, words out

This tool turns note data into sound. ParrotNotes works on speech: it records lessons, rehearsal debriefs or meetings (with the consent of the people in them), transcribes them and writes a summary.

Get ParrotNotes free

Related tools

MIDI to MP3 FAQ

Sources

MIDI to MP3 Converter

How to convert MIDI to MP3 or WAV

Drop the MIDI file

Set the tempo and render

Listen, then download