What Is a MIDI File?
A MIDI file (.mid or .midi) is a small file that stores music as notes — which key is played, when, for how long and how hard — but no recorded sound. A player or music app turns the notes into sound with its own instruments, so every note stays editable. Open one below to hear it and see its notes on a piano roll.
or drop a .mid file here. It stays on your device — nothing is uploaded.
What is inside a .mid file
A MIDI file is a Standard MIDI File: a header that starts with the letters MThd, followed by one or more tracks of time-stamped messages. These are the messages you will find in it.
Notes
Each note is a pair of messages: note on and note off. They give the pitch as a number from 0 to 127 (middle C is 60) and the velocity — how hard the key was struck, also 0 to 127.
Timing
Messages are spaced in ticks, a fraction of a beat set in the file header, and a tempo setting turns beats into seconds. Change the tempo and the whole piece plays faster or slower without changing pitch.
Tracks and channels
A file can hold many tracks, and each note is sent on one of 16 channels — usually one per instrument. In General MIDI, channel 10 is reserved for drums.
Instrument choices
A program change message picks one of the 128 General MIDI instruments for a channel: 1 is a grand piano, 25 a nylon guitar, 41 a violin. It names the instrument; it does not contain its sound.
Extra information
Meta events hold the tempo, time signature, key signature, track names, markers and sometimes lyrics as text.
MIDI vs MP3 and WAV
The piano example on this page is the same 20 seconds of music in both forms: 676 bytes as MIDI and about 321 KB as an MP3 — over 400 times larger, because the MP3 stores the sound itself.
| Property | MIDI (.mid) | MP3 / WAV |
|---|---|---|
| What it stores | Notes and instructions | Recorded sound |
| Size of 20 s of piano | 676 bytes | 321 KB |
| Sounds the same everywhere | No — each player picks its instruments | Yes |
| Edit single notes | Yes — move, delete or change any note | No — only cut, mix and apply effects |
| Can hold a recorded voice | No — only the lyrics as text | Yes |
| Plays on phones out of the box | Rarely | Yes |
How to open a MIDI file
Opening a .mid file needs an app with instruments to play the notes. Phones and many media players have none, which is why a MIDI file often seems not to open at all.
In your browser (any device)
Use the player at the top of this page, or the full online MIDI player. The file is read on your device and never uploaded.
Windows
Windows Media Player Legacy plays .mid files with the built-in Microsoft GS Wavetable Synth. For editing, open the file in a DAW such as FL Studio or Reaper, or in MuseScore to see it as a score.
Mac
QuickTime Player no longer plays MIDI. Open the file in GarageBand or Logic Pro: drag it onto the track area and each MIDI track becomes a software instrument track.
iPhone and iPad
There is no built-in MIDI player, so tapping the file in Files shows nothing useful. Play it in the browser player above, or import it into GarageBand for iOS.
Android
Android includes a basic MIDI synthesizer, so some music players and file managers can play .mid files, but it varies by phone. The browser player works on all of them.
DAWs and notation apps
Every DAW imports MIDI: FL Studio, Ableton Live, Logic Pro, GarageBand, Cubase, Reaper, Studio One. Notation apps such as MuseScore and Sibelius turn the notes into sheet music.
How to convert a MIDI file
To share a MIDI file with someone who has no music app, turn it into audio: the MIDI to MP3 converter plays every track with General MIDI instruments and drums and saves an MP3, all in your browser. To read the notes instead of hearing them, the MIDI to sheet music converter writes them out as a score you can print.
Going the other way — getting a MIDI file from a recording — means working out which notes are in the sound. The free MP3 to MIDI converter does that with a neural network; for a solo piano recording use the piano to MIDI converter.
More free MIDI tools
MP3 to MIDI Converter
Upload a song or recording as an MP3 and download its notes as an editable MIDI file.
Convert MP3 to MIDI →Audio to MIDI Converter
WAV, M4A, FLAC, OGG and the sound of MP4 or MOV videos, turned into MIDI notes.
Convert audio to MIDI →WAV to MIDI Converter
Lossless WAV and FLAC recordings and DAW stems, for the cleanest notes.
Convert WAV to MIDI →MP4 to MIDI Converter
Upload an MP4 or MOV video and get the notes in its sound track as MIDI.
Convert MP4 to MIDI →Piano to MIDI Converter
Solo piano recordings to MIDI, with chords and both hands as separate notes.
Convert piano audio to MIDI →Voice to MIDI Converter
Sing, hum or whistle a melody into your microphone and get it back as MIDI.
Convert your voice to MIDI →Online MIDI Player
Open a .mid file and hear it on a piano roll in your browser — nothing is uploaded.
Play a MIDI file online →MIDI to MP3 Converter
Play a .mid file with real instruments and drums and save it as an MP3 — in your browser.
Convert MIDI to MP3 →MIDI to WAV Converter
Render a .mid file to a lossless WAV for your DAW or a video, without uploading it.
Convert MIDI to WAV →MIDI to Sheet Music Converter
Turn a .mid file into a score you can read, print as a PDF or edit as MusicXML.
Convert MIDI to sheet music →Frequently asked questions
What does MIDI stand for?
Musical Instrument Digital Interface. It was introduced in 1983 so that synthesizers and computers from different makers could send notes to each other. The Standard MIDI File format (.mid) followed a few years later to save those messages to disk.
Is .mid the same as .midi?
Yes. Both extensions are used for the same Standard MIDI File format. You may also meet .kar (a MIDI file with karaoke lyrics) and .rmi (a MIDI file wrapped in a RIFF container on Windows).
Why does a MIDI file sound different on every device?
Because it holds no sound. Each player chooses its own instruments for the notes, so a cheap built-in synthesizer, a sample library in your DAW and this page all sound different. To fix one sound, render the file to audio with the MIDI to WAV converter.
Can a MIDI file contain vocals?
No. It can hold the melody of the vocal as notes and the words as text, but not a recording of the voice. To get a sung melody as MIDI notes, use the voice to MIDI converter.
What are MIDI file types 0 and 1?
A type 0 file puts every channel in a single track; a type 1 file keeps several tracks that play together, usually one per instrument. Type 2, separate patterns played one after another, is rarely used. Every common player and DAW opens types 0 and 1.
What about MIDI 2.0?
MIDI 2.0 was adopted in 2020 and adds finer resolution and two-way communication between devices. Almost every .mid file you will download or export is still a Standard MIDI File, which every tool on this site reads.
Piano sound: samples from Salamander Grand Piano by Alexander Holm, licensed under CC BY 3.0.