How to use the MIDI piano and monitor
Use this free MIDI keyboard tester to check whether your keyboard is sending MIDI data correctly. It can also act as a simple MIDI monitor while you work on music.
How do I connect a MIDI keyboard?
- Connect your MIDI keyboard to your computer with USB, or connect it through a compatible MIDI interface.
- Turn the keyboard on.
- Open this page in a browser that supports Web MIDI.
- Click Connect MIDI and allow MIDI access if your browser asks.
- Select your keyboard from the MIDI input menu.
- Press a key. The corresponding piano key should light up and the MIDI message should appear in the monitor.
What is MIDI?
MIDI is a protocol used by electronic musical instruments, controllers, computers, and music software to communicate musical performance information. A MIDI note message can tell software which note was played, on which channel, and with what velocity.
Test a MIDI keyboard for stuck or missing notes
Play every key one at a time and watch the virtual keyboard. If a physical key produces no MIDI message, or a key remains active after you release it, check the keyboard, cable, MIDI interface, and software configuration.
Use it as a MIDI monitor
The monitor shows incoming MIDI messages as they arrive. This is useful for checking note-on, note-off, controller, and other messages while troubleshooting a keyboard or MIDI controller.
Simple MIDI recording
Use Start Recording to capture incoming MIDI events while you play. The recorder is intentionally simple: it is designed for quick tests and monitoring rather than replacing a full digital audio workstation.
Browser and Web MIDI limitations
Web MIDI support depends on the browser and operating system. Some browsers and mobile devices do not expose Web MIDI. Browser permission settings may also prevent MIDI access. Device names, available ports, message types, timing, and mappings depend on the connected hardware. This tool does not create audio from your MIDI keyboard by itself; it displays MIDI data. It also cannot confirm a hardware fault with certainty.