Press keys — they light up. Green means tested. Find dead, stuck or repeating keys before you buy that used laptop or trust that new mechanical board.
🔒 Nothing is recorded or sent — keystrokes stay in your browser.
Note: your OS eats a few keys before the browser sees them (PrintScreen, F11, Cmd+Tab, Ctrl+W). That's normal, not a fault.
This keyboard tester checks every key on your keyboard right in the browser — no install, no driver, nothing to sign up for. Press a key and it lights up blue on the on-screen layout; once released it turns green so you can see at a glance which keys you've already tested and which have never responded. It's the fastest way to check a used laptop before you buy it, verify a new mechanical keyboard, or work out whether that one annoying letter is really dead.
Dead keys — anything that never lights up is not reaching your computer. Stuck keys — if a key reports pressed but never released, it's flagged in red and blinks. N-key rollover (NKRO) — hold several keys at once and the counter shows how many your board registers simultaneously; budget keyboards often cap at 2–3, gaming boards do 6 or more. Chatter / repeat — a switch that fires twice from one press shows as rapid flicker.
A handful of keys are swallowed by the operating system before any website can see them: PrintScreen, F11 (fullscreen), Cmd+Tab, Ctrl+W, and media keys on some laptops. That is expected behaviour and doesn't mean your keyboard is broken. If an ordinary letter, number or arrow doesn't respond, the key or its switch is the problem — try cleaning under the keycap first, since dust and crumbs cause most "dead" keys on laptops.
Related: All free tools