Hardware diagnostic
Key Press Test
Press any key to see exactly what your keyboard sent — the key, its physical code, and whether it's misbehaving. Ctrl and Cmd shortcuts stay live so you can still leave the page.
Press any key
Every key shows its name and code here. Test each key on your board — hold several at once to check rollover. Ctrl/Cmd shortcuts stay active.
Three checks worth running
The full sweep: press every key on the board once, in order. Each should show its correct name and code the instant you press. A key that needs force, registers late, or shows nothing has a dead or dirty switch; a key that shows the wrong code points at a remapping in software rather than a hardware fault.
The chatter check: tap each of your most-used keys twenty times at a relaxed pace. If a key re-registers within 45 ms of being released without you tapping that fast, it gets flagged — the keyboard equivalent of mouse double-click chatter, and the classic fault of worn mechanical switches. Repeatable flags on the same key mean the switch needs cleaning or replacing; double letters in your typing are the everyday symptom.
The rollover check: hold down several keys at once and watch the "currently held" counter. Gaming keyboards with N-key rollover track ten or more; budget boards may max out at six, or miss combinations of three keys on the same circuit row. If a key you're holding drops out of the count when another is pressed, you've found your board's ghosting limit — worth knowing before it eats a keystroke mid-game.