How to read it
- Key is the character or action the system produced; code is the physical position. If code is
KeyQbut key showsA, your layout is set to AZERTY — not a hardware fault. - Rollover is how many keys register at once. Cheap keyboards manage 2–6; gaming keyboards “NKRO” register all. Hold several letters together to see yours.
- A key that never lights here is not reaching the operating system: see keyboard keys not working to tell dirt from a dead matrix.
- A key that stays lit (down) after you release it is stuck — debris or a worn switch.
Keys that are special
Browsers reserve a few combinations: ⌘/Win shortcuts and some F-keys open system features before the page sees them. Fn itself produces no event on most laptops. Media and power keys may not register — that is normal.
Fix guides for this
Related tests
Questions, answered
Some F-keys open browser features instead of lighting up.
The browser or OS handles them first (F5 reload, F11 full screen, F12 dev tools). Try with “Typing mode” off, or test those keys in a text editor.
Numpad keys show as arrows.
Num Lock is off. Press it and the pad types numbers again.
Does this work for Bluetooth or phone keyboards?
Yes — anything the OS reports as a keyboard, including external keyboards on iPad and Android.