What Is NKRO?

NKRO (N-key rollover, Full rollover): N-key rollover — a keyboard's ability to register every key pressed at the same time, no matter how many.

Definition

Rollover is how many keys a keyboard can register at once. NKRO (n-key rollover) means there’s no practical limit — every key you hold is reported. A 6KRO keyboard reports up to six normal keys plus modifiers like Shift and Ctrl.

Why Some Keyboards Drop Keys

Keys are wired in a grid (a matrix). Without a diode on each switch, certain three-key combinations look ambiguous, so the keyboard blocks the extra key to avoid registering a phantom one — a problem called ghosting. Anti-ghosting keyboards add diodes so every key can be read independently.

Do You Need NKRO?

For most gaming, 6KRO is enough. NKRO matters for rhythm games, stenography and fast typists who briefly hold many keys. Some NKRO keyboards default to 6KRO for compatibility and need NKRO switched on in their software.

The key rollover test shows exactly how many keys your keyboard handles together.

Measure It

Related Guides

Mechanical vs Membrane KeyboardsBoth kinds of keyboard type letters, but they feel, sound, last and fail very differently. Here's how to pick.

DebounceThe short delay a keyboard or mouse uses to ignore switch contact bounce, so one press registers exactly once.

Part of the TapTest glossary · More in keyboard tests.