Look for phantom keys
Hold a chord and watch the detected list. If a key you never pressed appears, that is a visible phantom key event at the OS level.
Keyboard Ghosting Test
Ghosting happens when a keyboard matrix produces or drops keys in certain combinations. This workspace shows the combination currently detected and explains browser limitations clearly.
Mobile note: Ghosting detection requires a physical keyboard.
esc F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12
` 1 2 3 4 5 6 7 8 9 0 - = backspace
tab Q W E R T Y U I O P [ ] \
caps A S D F G H J K L ; ' enter
shift Z X C V B N M , . / shift
ctrl win alt space alt win menu ctrl
Detected state
Browser view Current held 0
Maximum held 0
Held keys None
Limitations: this panel reports keyboard events delivered by the operating system to
this browser tab. It cannot measure hardware matrix behavior, firmware promises, USB polling, or true
physical latency.
About this test
Drops are also evidence
A key that stops reporting while others stay held can indicate matrix limitations, though shortcuts and focus loss can look similar.
Keep claims honest
A browser cannot inspect the hardware matrix. It can only report the keyboard events the OS delivered to this page.
Related tools
Related guides
Is ghosting the same as rollover?
No. Rollover is about how many keys are reported; ghosting is about phantom or dropped keys in specific combinations.
Can the test fix ghosting?
No. It is a diagnostic tool. If you see consistent phantom keys, try the same chord on another keyboard before assuming the board is at fault.