GEARCHECK LABHold multiple keys at the same time and see exactly which keydown events reach your browser. Track the highest simultaneous count, test gaming combinations, and look for repeatable missing inputs that may indicate a rollover limitation or ghosting-related matrix conflict.
Rollover describes how many simultaneous keys a keyboard can report correctly. Ghosting commonly describes matrix behavior where a real key is blocked or an unintended key appears for a particular combination.
Advertised 6KRO or NKRO does not guarantee identical behavior across every matrix region, firmware profile, adapter or wireless mode. Judge the combinations you actually need.
| Observed pattern | Reasonable interpretation | Useful next check |
|---|---|---|
| Every tested key stays visible together on three attempts | That exact combination reached this browser successfully. | Repeat the real in-game or shortcut combination you care about; do not generalize to untested matrix positions. |
| The same key disappears only in one larger combination | A repeatable rollover or matrix-region limit is possible. | Test smaller subsets, swap left/right modifiers, and compare another connection mode. |
| A missing key changes between attempts | Focus loss, release timing, wireless interruption or software interception is more plausible than one fixed conflict. | Release all keys, refocus the test area, close remappers and repeat slowly. |
| A shortcut never reaches the page | The browser or operating system may reserve it before the page receives an event. | Use neutral letter combinations and compare the keys individually in the Keyboard Test. |
| An extra key appears repeatedly | A matrix, firmware or remapping issue may be involved, but this page cannot identify the physical source. | Check profiles/macros, try another computer and document the exact combination. |
This tool reads browser-visible keydown and keyup events while this page is open. It cannot inspect the keyboard matrix, switch contacts, firmware scan cycle, USB packets, radio quality or electrical signals.
Browser and operating-system shortcuts can be intercepted before the page receives them. Maximum counts describe only combinations actually exercised in this session, not a certification of 6KRO or NKRO.
All combination history and counters stay in this page. Do not type passwords or private text; use deliberate test keys only. The page does not upload keystroke content.
Keyboard ghosting is a keyboard-matrix or input-path behavior where a held combination blocks a real key or produces an unintended key. This page can show only the key events that reach the browser.
No. The maximum proves only that the combinations you tried reached this browser. It does not certify every matrix position, every connection mode or a manufacturer N-key-rollover claim.
The keyboard matrix may block it, but a browser shortcut, operating-system shortcut, accessibility feature, remapping utility or connection mode can also consume or change the event.
Some combinations are reserved before the webpage receives them. Repeat the test with a neutral letter combination and compare the same physical keys in another application or keyboard tester.
Yes. Firmware profiles, connection modes, adapters and power-saving behavior can expose different rollover limits. Compare the same named combination and keyboard settings in each mode.
An attached physical keyboard may expose useful events, but an on-screen keyboard does not reproduce physical switch-matrix behavior. Desktop browsers are usually the clearest comparison environment.