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 · Power users
Macro-Heavy MMO Chords: A Rollover Stress Test for Power Users
MMOs and creative suites stack Shift+Ctrl+alphanumeric keys. Inventory your worst chords, stress-test them in the rollover lab, and remap before raid night or deadline crunch.
Read guide
Keyboard Rollover · Modifier chords
Shift + Arrow Ghosting: Why Fighting Games and RPGs Miss Inputs
Shift plus arrow ghosting breaks menu navigation and fighting-game inputs on weak matrices. Test modifier chords in the rollover lab, disable software filters, and remap only after you measure.
Read guide
Keyboard Rollover · Rhythm & arrows
Rhythm Games and Keyboard Rollover: When Overlap Beats Raw Speed
Rhythm games need dense arrow overlaps—not raw WPM. Test Space+arrow chords, separate timing from rollover limits, and know when hardware beats speed.
Read guide