MIDI Monitor & Keyboard Tester
Read complete local MIDI messages, test notes and controls, and silence every channel.
Clock messages are counted without expanding display rows.
Hold a key with pointer or Enter/Space, then release. Notes show MIDI numbers and velocity; every full input message stays in the log.
No device events yet.
The displayed window is limited for readability. Every recorded event stays in the complete local session; no device sample is fabricated.
About the MIDI Monitor & Keyboard Tester
Check MIDI notes, velocity, pedals and controls across ports; inspect complete local messages and send deliberate test notes.
Web MIDI needs browser support and a secure context. SysEx access is optional and must be granted separately; no hardware identity is inferred. Readings come from the actual device events exposed to this page. Keep the original device settings and complete raw log when reviewing a result; displayed windows are only a readable view of the full session.
How to use it
- Connect your MIDI devices and request access yourself; enable System Exclusive only when you need its additional permission.
- Choose one input or every connected port. Press keys and pads, turn controls and use pedals; note names, channels and exact bytes are retained.
- Choose an output to send test notes, or enable browser audio to hear the input. Pitch bend, aftertouch, programs and clock counts remain distinct.
- Use all-notes-off before changing devices. Reset or export the complete message log; fast clocks are counted rather than expanded into display rows.
Limitations
- Web MIDI needs browser support and a secure context. SysEx access is optional and must be granted separately; no hardware identity is inferred.
- Permissions, policy, drivers and physical device delivery require real browser/device release checks.
- No compatibility certificate or inferred hardware fault is produced from timing or a single observed value.
Privacy
On this device: nothing is sent
MIDI bytes and observed messages stay in this browser. Only deliberate test actions send data to the chosen local MIDI output.
Frequently asked questions
Does the tool send device data to a server?
No. Device events, bytes and local records stay in this browser. Export them deliberately when you need support.
What does an unsupported browser show?
The actual capability and permission error is explained. No fabricated device reading replaces an unavailable API.