MIDI 键盘测试
验证 USB MIDI 键盘——实时显示 note-on / note-off 事件。
How this test works
Click Enable MIDI and grant permission. The page lists every connected input/output and prints the last 20 note-on / note-off events with their MIDI note number and velocity. Use it to verify that your USB or Bluetooth keyboard is actually delivering data before you start playing the harmonium.
FAQ
常见问题
Which browsers support Web MIDI?
Chrome, Edge, Opera, Brave and (since v126) Safari support Web MIDI without flags. Firefox needs <code>dom.webmidi.enabled</code> set in <code>about:config</code>. Mobile Chrome on Android also works with USB-OTG cables.
My controller is not appearing — what should I check?
Reconnect the cable and reload the page. Confirm the controller works in your OS sound settings (or in any DAW). Some Bluetooth MIDI keyboards need to be paired in OS settings before browsers see them.
Is anything sent over the network?
No. Web MIDI runs entirely in your browser — note events stay on your device. Play Harmonium Online does not log MIDI input.