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MIDI Monitor: Note and CC Messages

Connect MIDI inputs (no sysex) and watch notes and CC messages decode live. Teardown removes every listener.

Connect

Connect attaches this page to your MIDI inputs. The browser may prompt for access on the press. Play notes or move CC knobs on a connected controller and the messages appear in the table below, decoded.

idle
Rules this tool follows
  • requestMIDIAccess({ sysex: false }); system-exclusive messages are never requested, so this page cannot send or receive device firmware data even if a device offers it.
  • Chromium prompts for MIDI on first access; Firefox keeps a setting. Denied or unavailable states are named, never retried behind your back.
  • Stop removes every input listener and drops the access object. MIDI inputs themselves are owned by the browser, not this page; closing the page can never leave a port 'held'.
  • Messages live in this page’s memory, capped at 120 rows: Stop or navigation clears them.
Nothing in yet

Paste, drop, or type to begin. Everything stays on this device.

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