Free browser lab
Keyboard rollover & ghosting guides
Learn how simultaneous key presses behave on your board—blocking, phantom inputs, and NKRO claims—then stress-test chords in the free rollover lab before timed typing or competitive play.
Free tool
Stress-test chords for ghosting and dropped keys
Hold WASD or custom chords—we show which keys registered, which dropped, and any phantom inputs the browser received.
Step 1
Pick a chord preset
Start with WASD or record your own multi-key combo.
Step 2
Hold all keys together
Press and hold every key in the chord at once.
Step 3
Check for ghosts or drops
See missing keys or inputs you never pressed before blaming lag.
No download or sign-in. Chatter from one key is debounce—use the debounce lab for that.
How to test WASD chords in the browser →
Keyboard Rollover · How-to test
Test WASD Chord Rollover With a Free Browser Check: Step-by-Step
Run the WASD preset in the free rollover lab, read teal orange and red highlights, retest on your real connection, and know when matrix limits mean new hardware—not skill issues.
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Keyboard Rollover · NKRO definitions
N-Key Rollover Explained: NKRO, 6KRO, and What Gamers and Typists Actually Need
NKRO promises every simultaneous press registers—learn how firmware, USB, and wireless stacks limit real rollover, when six-key is enough for prose
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Keyboard Rollover · Ghosting basics
What Is Key Ghosting? When Keys You Never Pressed Still Register
Key ghosting explained: phantom inputs from matrix limits, how ghosting differs from sticky keys, safe reproduction in the rollover lab, and when to stop blaming software.
Read guide
Keyboard Rollover · Office use
Is Six-Key Rollover Enough for Office Work and Live Chat? When 6KRO Passes and When to Upgrade
Office prose and support chat rarely exceed six simultaneous keys—learn which Shift+Ctrl shortcuts expose weak matrices, how to test your real chord list
Read guide
Keyboard Rollover · Mechanical & wireless
Mechanical Keyboard NKRO: USB vs Bluetooth in Real Rollover Tests
Mechanical switches do not guarantee NKRO—compare USB HID modes and Bluetooth firmware limits, verify max simultaneous keys in the rollover lab, and separate rollover from latency upgrades.
Read guide
Keyboard Rollover · Laptops
Laptop Keyboard Rollover: Why WASD and Arrow Chords Fail First
Thin laptop matrices choke on gaming clusters and arrow chords before letter keys fail. Learn which zones share traces
Read guide