N-Key Rollover Test
Test your keyboard's N-Key Rollover (NKRO) online. See how many keys your keyboard can register simultaneously. Essential test for gamers and fast typists.
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N-Key Rollover Test — Check How Many Keys Your Keyboard Registers at Once
Check performance hardware specs, optimize key inputs, and verify your configurations in real-time with our free tools.
What Is N-Key Rollover?
N-Key Rollover (NKRO) is the ability of a keyboard to register multiple simultaneous key presses correctly. A full nkro test ensures that no matter how many keys you hold down at once, every single input registers with zero missed keys.
How to Use the NKRO Test
Click inside the test container and press as many keys as you can at the same time. The counter on our n-key rollover checker will show the maximum number of active registrations. Use this rollover test to verify if your keyboard is ready for fast typing.
N-Key Rollover vs 6-Key Rollover — What's the Difference?
A 6-Key Rollover (6KRO) keyboard can only register up to 6 keys at once. A full N-Key Rollover (NKRO) keyboard has no limit, registering all pressed keys simultaneously. NKRO is the standard for mechanical gaming keyboards.
Why NKRO Matters for Gaming
In fast-paced games, you often need to hold down multiple movement keys while tapping action keys. If your keyboard lacks anti ghosting and rollover support, some keys will fail to register, causing input lag.
Does My Keyboard Support Full NKRO?
Most modern USB mechanical keyboards support NKRO, while cheaper membrane keyboards are usually limited to 2KRO or 6KRO. Check your keyboard specs to confirm.
USB vs PS/2 Rollover Limits
Older USB protocols limited keyboards to 6KRO. Modern USB technology allows full NKRO, matching the performance of older PS/2 connections.
Which Gaming Keyboards Have Full NKRO?
Almost all mechanical gaming keyboards from brands like Corsair, Razer, and Logitech feature full NKRO over USB.
What to Do If Your Keyboard Fails the Rollover Test
If your keyboard registers fewer than 6 simultaneous keys, check if you need to enable NKRO mode using the keyboard's software (like Razer Synapse or Logitech G HUB).
Frequently Asked Questions
What is N-Key Rollover on a keyboard?
NKRO is the hardware capability of a keyboard to register every single key pressed simultaneously without missing inputs.
How do I test N-Key Rollover online?
Open our NKRO test page, hold down multiple keys at once, and check the maximum simultaneous key counter.
Does USB limit N-Key Rollover?
Older USB standards did, but modern keyboards use custom controllers to support full NKRO over USB.
Do I need full NKRO for gaming?
Yes, games often require holding movement keys while pressing action keys, making NKRO essential to avoid input lag.