Keyboard Tester
Press each key and watch it light up on a full virtual keyboard — a fast way to find dead, stuck, or chattering keys and check for ghosting.
Press any key to light it up. Click the keyboard so Space and arrows test here instead of scrolling the page — press Tab or click away to exit.
Recent keys
Press keys to see them logged here.
A keyboard tester checks that every physical key actually reaches the computer. Keys fail in predictable ways — debris under the keycap, worn or oxidised contacts, a spill, a flaky cable or wireless link — and show up as dead keys that never register, stuck keys that repeat on their own, or chattering keys that fire twice per press. Testing in the browser confirms the fault is the keyboard itself before you clean, swap switches, or file a warranty claim.
Click the keyboard to focus it, then press your keys. Each press is matched to the physical key by its hardware code, so the left and right Shift, Ctrl, and Alt are told apart and the numpad is separate from the number row. A key lights up while held and stays filled once tested, so you can track progress across the whole layout. The panel shows each key's key, code, and keyCode values plus live Caps, Num, and Scroll Lock status. Everything runs locally — no keystroke leaves your machine.
Hold several keys down at once to test rollover — how many simultaneous presses your board reports. Budget keyboards cap at 2 or 6 keys; boards with N-key rollover register them all. If holding three nearby keys lights up a fourth you never pressed, that's ghosting: a switch-matrix limitation that can silently drop inputs during fast typing or gaming.
Key rollover compared
| Rollover | Typical keyboards | What it means |
|---|---|---|
| 2KRO | Budget membrane and laptop keyboards | Two keys guaranteed; a third nearby press may be dropped or ghost |
| 6KRO | Most mainstream office keyboards | Six letter keys plus modifiers at once — plenty for normal typing |
| NKRO | Mechanical and gaming keyboards | Every key registers independently, no matter how many you hold |