How to use
- Pick the layout closest to your keyboard. Detection works on any layout; only the labels change.
- Press each key once. Tested keys stay marked; the counter shows what is left.
- Hold several keys at once to read your maximum rollover.
- Type normally for a while. Any key that registers twice within the threshold is listed as chatter.
Frequently asked questions
Why does a key not light up?
Some keys never reach the browser: Fn is handled inside the keyboard, and some systems reserve Print Screen, the Windows key or media keys. If a regular letter key does not light up, it is likely faulty.
What is n-key rollover?
It is how many keys the keyboard can report at the same time. Office keyboards often stop at 6 keys or show ghosting with certain combinations; gaming keyboards usually support all keys (NKRO).
What is key chatter?
A worn or dirty mechanical switch can send two presses for one. The detector flags presses of the same key that come faster than the threshold, which is 50 ms by default.