Keyboard Tester

Verify key actuation, benchmark simultaneous N-Key Rollover (NKRO), and test input matrix ghosting.

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Peak (NKRO)
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TierReady
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Keyboard Rollover Hierarchy

N-Key Rollover & Actuation Performance

Comparing simultaneous key actuation caps and matrix ghosting characteristics across keyboard switch architectures.

Pro Tier Hierarchy
Hardware ModelRollover CapacityActuation TravelDebounce DelayOur rating
1
Wooting 60HE+ / Apex Pro (Hall Effect Magnetic)True NKRO + Rapid Trigger
Full NKRO0.1mm – 4.0mm Dynamic0ms Contact Delay
Tier S+ (Esports Pro)
2
Custom Mechanical (Dioded PCB / QMK)Full Mechanical NKRO
Full NKRO1.5mm – 2.0mm Fixed1ms – 3ms Debounce
Tier S (Enthusiast)
3
Standard USB Gaming Keyboard6KRO / 10KRO
6KRO + Modifiers2.0mm Fixed5ms Debounce
Tier B (Standard Gaming)
4
Membrane / Laptop KeyboardMatrix Limited
2KRO – 3KROMembrane DomeGhosting Prone
Tier D (Membrane Office)
Ratings are our editorial opinion based on manufacturer specs.
Related Engineering GuideHall Effect vs Mechanical Switches: Rapid Trigger & Magnetic Actuation Explained
Read Rapid Trigger Guide
Matrix Science

Understanding Keyboard Rollover & Ghosting

N-Key Rollover (NKRO)

Unlimited Inputs

NKRO ensures that every single key pressed simultaneously is registered by the OS without key blocking or missing inputs.

Matrix Ghosting

Circuit Limitation

Ghosting occurs on membrane keyboards when pressing multiple keys on a shared grid causes an unpressed adjacent key to register falsely.

USB 6KRO Limit

Legacy USB Spec

The standard USB Human Interface Device (HID) boot protocol only supports 6 simultaneous alphanumeric keys plus modifier keys. Modern gaming keyboards bypass this by emulating multiple virtual HID devices or utilizing custom multi-byte USB descriptors.

Debounce & Actuation Point

Switch Response

Mechanical switch contacts bounce when struck. Keyboard microcontrollers apply a digital debounce algorithm (typically 1ms to 5ms). Magnetic Hall Effect and optical keyboard switches actuate with zero physical contact, delivering instant response without debounce delay.

FAQ Reference

Keyboard Tester Frequently Asked Questions

What is N-Key Rollover (NKRO)?
NKRO means a keyboard can detect every key pressed simultaneously without key ghosting or matrix limitations.
What is key ghosting and how does it differ from key rollover?
Key ghosting occurs when pressing multiple keys on an unbuffered membrane matrix causes an unpressed adjacent key to trigger. Key rollover (e.g. 6KRO or NKRO) defines how many simultaneous presses the keyboard controller accurately registers.
Can mechanical keyboard switches experience key chatter or double-pressing?
Yes. Similar to mouse microswitches, dirty or degraded mechanical keyboard switch leaves can bounce, causing a single keypress to register twice. Cleaning with isopropyl alcohol or replacing hotswap switches solves this.
What is the difference between 6KRO and NKRO?
6KRO limits the keyboard to registering a maximum of 6 simultaneous letter/number keys plus modifier keys (Ctrl, Shift, Alt). NKRO (N-Key Rollover) allows every single key on the keyboard to be pressed simultaneously without any input drops.
How does Rapid Trigger differ from standard mechanical switch actuation?
Standard mechanical switches actuate at a fixed point (e.g. 2.0mm) and must release past a fixed reset line (e.g. 1.5mm). Rapid Trigger dynamically resets the instant the key moves upward by as little as 0.1mm anywhere along the travel path, allowing near-instant counter-strafing.