How to use
- Connect the keyboard or controller by USB (or a MIDI interface) before opening the page.
- Press "Connect MIDI" and allow access when the browser asks.
- Play every key. Tested keys get a green mark; press softly and hard to check the velocity range.
- Move knobs, faders, the pitch wheel and pedals. Each message appears in the log.
- To test MIDI out, choose an output and play the scale, or click the keys on the screen.
Frequently asked questions
My keyboard is not listed.
Web MIDI works in Chrome, Edge, Opera and Firefox. Safari does not support it. Close DAW software that may hold the device exclusively, reconnect it and reload the page.
One key always plays at the same velocity.
If a key never goes below or above a certain velocity while the others do, its sensor or rubber contact is likely worn. Velocity curves set in the keyboard can also limit the range.
What is CC 64?
Control change 64 is the sustain pedal: 0 means released and 127 means pressed. Half-pedal capable pedals send values in between.