Are All My Keyboard Keys Working?
Press any key and see it light up instantly. This test uses the KeyboardEvent API to detect every keypress, tracks N-key rollover count, and highlights untested keys — all processed in your browser with zero data uploads.
This test detects individual key registration, keyCode values, key names, and simultaneous key count (N-key rollover) using the browser KeyboardEvent API.
USB keyboards typically support 6-key rollover (6KRO), while gaming keyboards with NKRO report all 104+ keys pressed simultaneously.
Start Test
What Do Your Results Mean?
| Result | Range | Meaning |
|---|---|---|
| Good | All keys register and NKRO matches spec | Every key sends a valid KeyboardEvent and your rollover count matches the manufacturer rating — your keyboard is fully functional. |
| Warning | 1–3 keys unresponsive or rollover below expected | A few keys may have debris or worn switches. Clean the affected keys or test with an external keyboard to rule out software issues. |
| Bad | Multiple keys dead or rollover stuck at 1–2 | Multiple failed keys indicate hardware damage — switch failure, broken traces, or a faulty USB controller. Consider replacing the keyboard. |
Common Issues and How to Fix Them
A key does not register at all
Remove the keycap and clean the switch with compressed air. If it still fails, the switch may need replacement (mechanical) or the membrane contact is damaged.
Fn key or media keys are not detected
These keys are intercepted by the OS or keyboard firmware before reaching the browser. This is normal — browsers cannot capture Fn, Print Screen, or certain media keys via KeyboardEvent.