Multi-key combination diagnostic
Hold several physical keys together and see which ones reach the browser. Guided tests let you compare a known expected combination with what was actually detected.
Combination test
Swipe sideways to view the full keyboard.
The page can display only keys reported by the browser. In guided mode, compare the known requested combination with what was detected.
Understanding combinations
When several keys are held, a keyboard matrix may fail to report one of them or may historically report an unintended key. Modern keyboards often use blocking to suppress ambiguous signals, so a missing input is not always “ghosting” in the strict sense.
Ghosting traditionally means an unintended extra key. Blocking means the keyboard deliberately withholds an ambiguous key to prevent that false input. From a browser, both are best discussed as a possibly blocked combination unless the expected input is known.
Use Free test to explore any combination. In Guided test, select a suggestion, hold every listed key together, release them, and record the best attempt. The comparison uses only that explicitly requested combination.
Games and some shortcuts require movement, modifiers, and actions at the same time. “Anti-ghosting” usually applies to particular matrix zones or combinations; the exact coverage varies by keyboard.
Keys in one matrix path may conflict while a nearby arrangement works. Connection mode, firmware, keyboard layout, and hardware design can also change which combinations are reported.
A limitation matters when it affects keys you actually need together. Test your real gaming, work, or accessibility combinations rather than treating one synthetic failure as proof of general hardware damage.
The browser cannot observe a physical key the keyboard never reports, and system shortcuts may be intercepted first. Current key sets and guided results remain only in page memory; no key labels or combinations are sent to a backend.