Keyboard & NKRO Rollover Test
Test every key on your keyboard. Check for key ghosting, N-Key Rollover (NKRO) simultaneous key presses, key repeat rate, switch response latency, and synthesize mechanical switch sounds.
How to Use This Test
- Press any key on your keyboard. The corresponding key lights up in real time and turns green to indicate it is functioning properly.
- Press modifier and navigation keys (Shift, Ctrl, Alt, Windows, Tab, Space, Arrows, Delete) to ensure no switches are dead.
- Test Multi-Key Rollover: Press and hold multiple keys simultaneously (e.g.
W + A + Shift + Space) to see how many keys your keyboard can register at once. - Toggle the Mechanical Switch Sound checkbox if you want audio click feedback as you type.
What Is Keyboard Ghosting & Key Jamming?
Standard office membrane keyboards connect keys in an electrical grid matrix. When you press three or more keys that share common rows and columns, the keyboard may fail to register an additional press (key jamming) or falsely trigger a key you never pressed (ghosting). In games, this can prevent you from sprinting diagonally while jumping.
NKRO (N-Key Rollover) vs. 6KRO
6KRO (6-Key Rollover) is standard for basic USB keyboards, allowing up to 6 keys to be pressed at once. NKRO (N-Key Rollover) is featured on mechanical gaming keyboards, allowing every key on the entire board to be pressed simultaneously with zero missed keystrokes.
Diagnosing Sticky or Chattering Keys
If a key on screen stays lit or flashes repeatedly after a single light press, the physical switch stem may be stuck from dust or liquid spills, or the mechanical leaf spring has contact chatter. Cleaning under the keycap with compressed air or isopropyl alcohol often restores normal operation.