Keyboard Rollover & Ghosting Lab

Diagnose hardware limits, log custom key combinations, check for N-Key Rollover (NKRO), and test your layout with dynamic audio feedback.

Keys Held 0
Max Rollover 0
Rollover Verdict None
Last Key Code ---
⌨️

Click to Activate Key Capture

Ensure this window has focus to begin recording key rollover and block default browser scrolling shortcuts.

Esc
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PrtSc
ScrLk
Pause
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Ghosting Checkpoints

Gaming & professional keyboard presets. Press all keys in the set simultaneously to see if your keyboard registers them without blocking/ghosting.

WASD + Space Pending
WASDSpace
Essential movement combo for FPS games.
Arrows + Space Pending
▲◀▼▶Space
Common control scheme for arcade and racing games.
L-Shift + W + A + Space Pending
L-ShiftWASpace
Sprint + Diagonal Jump combo, highly prone to ghosting.
Home Row Rollover Pending
ASDFJKL;
Tests typist home row compatibility (8 simultaneous keys).
Tri-Modifiers + Esc Pending
CtrlShiftAltEsc
Common advanced system shortcut combination.
L-Ctrl + L-Shift + Z + X + C Pending
L-CtrlL-ShiftZXC
Bottom corner cluster, tests dense matrix tracing.

Audio Feedback

60%

Keystroke Logger

[SYSTEM] Diagnostic Terminal Initialized. Ready for inputs...
[SYSTEM] Mechanical switch click synthesis loaded.
ACTIVE
Pressing keys will bypass browser defaults

What is Keyboard Ghosting & Key Rollover?

Keyboard Ghosting

Ghosting occurs when you press multiple keys on a keyboard simultaneously, and some keys fail to register. This is a design limitation in matrix keyboards where the electrical circuits overlap, causing the controller to become "blind" to certain positions to prevent registering keys that were not pressed ("ghost keys").

Key Rollover (KRO)

Key Rollover is a measure of how many simultaneous keys a keyboard can register. A keyboard with 2-Key Rollover (2KRO) can register any 2 keys at once. Higher-end models feature 6KRO or N-Key Rollover (NKRO), meaning you can press any number of keys simultaneously, and all will be read correctly.

How to Diagnose Ghosting

Click on the virtual keyboard to focus it, and hold down your keys. If you press standard gaming configurations (like W A S D and Space together) and some keys are not highlighted in cyan, your keyboard is ghosting. Check the checkpoints panel to verify your hardware capabilities!