MyDeviceScan / Keyboard Test

Keyboard Test

Press keys to confirm that your keyboard is sending input correctly. This browser-based test highlights pressed keys, shows key codes, counts simultaneous keys, and helps spot stuck or unreliable keys.

How to Check a Keyboard

Press each key once and confirm that the matching key lights up. Test letters, numbers, modifiers, arrows, function keys, and the spacebar. If a key does not react, try another browser or text editor to confirm whether the issue is browser-specific or hardware-related.

For gaming keyboards, hold several keys at the same time. The Pressed Now and Max Held counters help you compare simultaneous input behavior. Some inexpensive keyboards cannot report certain key combinations because of matrix ghosting limitations.

Common Keyboard Problems

A stuck key may remain highlighted after release, while a failing switch may appear only when pressed hard or at an angle. Wireless keyboards can also miss input when the battery is low, the receiver is far away, or there is interference from hubs and metal desks.

This tool reads browser keyboard events, so system shortcuts may be intercepted by the operating system before the page receives them. That is normal for keys such as brightness, volume, and some platform-specific function shortcuts.

FAQ

Keyboard Test — Frequently Asked Questions

Why are some of my keys not showing up?

Press each key on its own first. If a key registers alone but disappears when you hold others, that's keyboard ghosting — the keyboard can't detect that specific combination. If a key never registers at all, it may be dead or the switch has failed.

What is keyboard ghosting and rollover?

Ghosting is when pressing several keys at once causes some not to register, because the keyboard's wiring matrix can't tell them apart. Gaming keyboards with N-key rollover (NKRO) avoid this and register every simultaneous press.

Does this detect stuck keys?

Yes. A key that lights up on the tester without you pressing it, or one that stays highlighted after release, indicates a stuck or faulty key — often caused by dust or debris under the keycap.

Does it work for laptop and external keyboards?

Yes, it tests whatever keyboard is connected to your device — laptop, USB, or Bluetooth. Click anywhere on the page first so it can capture key events, then start pressing keys.