Reader
What's inside your .mid file?
Drop in a Standard MIDI File and read it like a book: the header, every track and instrument, tempo and key changes, controllers, SysEx, and each event down to the byte. Play it back with sampled instruments or your own MIDI gear. Everything happens in your browser.
Open a file
Drop a .mid file here to replace it
Read in your browser. Nothing is uploaded.
Or open a demo file
Overview
The header chunk, byte by byte
14 bytes
Every Standard MIDI File starts with a 14-byte MThd chunk. It says how the tracks relate (the
format), how many track chunks follow, and how to turn ticks into time (the division).
Piano roll
Each bar is a note: height is pitch, length is duration, brightness is velocity. Drums (channel 10) sit in the strip at the bottom. Click to jump there.
Tracks
Export & convert
.mid · CSV · JSON
Save a new file with only the tracks you want, transposed or at another tempo, or convert the file to text. The original is never changed.
CSV uses the record format of John Walker’s midicsv, so csvmidi can turn it back into a file. JSON lists each track’s events with ticks, seconds and decoded fields.
Tempo, meter & key
Meta events
Meta events (FF type length data) live only in files: names, lyrics, markers, tempo and signatures.
They are never sent to instruments.
Controllers & pitch bend
Every continuous control stream in the file, per channel, with how often it changes and the range of values it covers.
System Exclusive
SysEx events carry manufacturer-specific data, such as GM/GS/XG resets and patch settings. In a file they are stored
as F0 length data; the length is not sent.
Events & bytes
Select an event to see exactly which bytes encode it, or click any byte in the hex view to find its event.
No event selected.
Keyboard shortcuts
- Space
- Play or pause
- ← or →
- Back or forward 5 seconds
- Home
- Back to the start
- Click a byte
- Find its event