How to test your keyboard
- Press each key on your keyboard. Keys light up while held and turn green once they have registered.
- Check the counter: when every key on your keyboard is green, they all work. Keys your keyboard does not have, such as a numeric keypad on a laptop, simply stay grey.
- Hold several keys together to test rollover (how many simultaneous keys are detected), and watch the chatter check for keys that register twice from one press. Click and scroll in the mouse box to test mouse buttons and the wheel.
Finding keyboard faults
A key that does not light up is either not connected, physically damaged or blocked by dirt or a spill. Try a few firm presses, clean around it with compressed air, and on laptops check for a stuck key cap. If keys produce the wrong character, your keyboard layout setting in the operating system may not match the physical keyboard, which is common when switching between UK and US layouts: the code shown for the last key tells you which physical key was pressed.
Chatter, a key that types two letters from one press, is a common fault in worn mechanical switches and is flagged when the same key registers twice within 30 milliseconds. Rollover matters for gaming and fast typing: many cheaper keyboards detect only a few keys at once, and some combinations fail ("ghosting"), while gaming keyboards often support six or all keys simultaneously (NKRO). A few keys, such as Print Screen or some laptop function keys, may be handled by the operating system before the browser sees them. Everything runs locally.
Why do some keys not light up?
They may be faulty, missing from your keyboard, or captured by the operating system (such as Print Screen, Fn and media keys).
What is key rollover?
The number of keys a keyboard can register when pressed at the same time. 6-key rollover or N-key rollover is good for gaming.
How do I fix keyboard chatter?
Clean the switch, or on mechanical keyboards replace the switch or use debounce settings in the keyboard software.