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GEARCHECK LAB
GearCheck Lab // Browser diagnostic

MIDI Keyboard & Controller Test

Check whether notes, velocity, pedals and control messages reach a browser with Web MIDI support. Access is requested only when you start, and the test listens to inputs without sending commands to MIDI outputs.

MIDI Keyboard & Controller Test workbench

Free / No account
READY — choose an action below

No input access requested.

Messages received0
Last note number—
Last note velocity—
No MIDI input received.

Input only. No system-exclusive access or MIDI output commands.

How to use this tool

  1. Connect the MIDI keyboard or controller and choose Start MIDI input.
  2. Decide whether to grant the browser’s MIDI permission prompt.
  3. Play notes, vary the strike strength and move a controller or sustain pedal.
  4. Review the channel and event log, then stop listening before using another application.

Read the result correctly

Note-on messages with nonzero velocity update the displayed note number and velocity. Note-on with zero velocity is interpreted as note-off, as is the dedicated note-off command. Controller messages show controller number and value; sustain controller 64 is labelled on at 64 or above. These are received MIDI values, not measurements of physical key force. Pitch-bend messages show the combined 14-bit value.

Limits and troubleshooting

Web MIDI is not exposed by every browser and can be blocked by permission or site policy. An absent input may reflect a driver, cable, device mode or another application rather than a failed keyboard. This page does not request system-exclusive access, edit device configuration, play a synthesizer or test MIDI audio output. It lists connected inputs only after permission, stops listeners when hidden and keeps the recent message log in this tab.

Frequently asked question

Will this send settings to my instrument?

No. It requests input access without system-exclusive permission and does not send MIDI output messages or configuration commands.

Privacy and control

Diagnostic data is processed locally in this tab and is not intentionally sent to analytics. Network tools send only their test probes and temporary payloads to GearCheck Lab’s speed-test server. Media and device access starts only after your explicit action and any required browser permission. Downloaded results stay on your device.

Read the privacy policy and testing methodology. If something fails, report the tool URL and visible message.