About the tool
About Keyboard Tester Online
Keyboard Tester Online is a fast browser-based utility for checking whether every key on a physical keyboard responds correctly.
What it can help with
Broken keys
Press a key and see whether the matching on-screen key lights up.
Special keys
Check function keys, arrows, modifiers, numpad keys, and other special keys.
Key codes
View event.key, event.code, keyCode, repeat state, and focus status.
How it works
The tester listens for keyboard events in the browser and highlights keys by physical position using event.code. That means the visual key position stays consistent even if your keyboard language changes.
Some operating-system shortcuts, especially screenshot keys, may be intercepted before a browser can read them. When the browser exposes the event, the tester flashes the matching key.