Use this tool to identify which key is sending repeated signals. If a key lights up red
without you touching it, it is physically stuck. Try cleaning under the keycap with
compressed air or isopropyl alcohol to remove debris causing the constant input.
N-Key Rollover (NKRO) is your keyboard's ability to register multiple simultaneous key
presses. The counter shows the maximum number of keys pressed at the same time. Try pressing
multiple keys together - gaming keyboards typically support 6+ keys, while premium
mechanical keyboards can handle 10+ simultaneous presses.
"Tested keys" shows how many keys you've pressed at least once (marked with a green border).
"Active keys" shows keys currently being held down. Tested keys help you track which keys
you've verified are working properly.
Ghosting happens when a keyboard fails to register multiple simultaneous presses. To test
this, press and hold 3 or more keys at once (like W, A, S, and D) on this page. If any key
fails to light up while held, your keyboard is experiencing ghosting.
This is called "key chatter," common in mechanical keyboards. Watch the Event Log on this
page while typing. If you see two "keydown" events appear instantly for a single press, the
switch contacts are dirty or failing and may need replacement.
No. Everything runs locally in your browser. No data is stored, collected, or transmitted to
any server. Your keyboard testing is completely private and secure. You can even use this
app offline after the initial load.