Online Keyboard Test & Ghosting Detector

It's a defect that occurs when you press multiple keys at once and the computer doesn't register some of them. It's due to limitations in the keyboard's internal electrical matrix that cannot process certain combinations.

NKRO means the keyboard can register as many keys as you can press simultaneously without failure. It's a premium feature, common in high-end mechanical and gaming keyboards.

Most cheap office keyboards have a 2 or 3-key rollover. This is sufficient for typing but insufficient for intensive gaming or complex shortcuts.

If the test doesn't detect the keypress, it could be dirt under the switch, electrical contact failure, or a damaged cable. Try cleaning the keyboard with compressed air before giving up.