Keyboard lab
Simultaneous key and rollover test
Observe which keys the browser reports held together and the highest simultaneous count in a trial.
How to use this check
Start, focus the keyboard area, then press keys. Tab or Escape ends the test. Nothing typed outside this area is recorded.
What the browser measures
Click here after starting. The drawing shows physical key positions; key and code may differ on your layout. Numeric keypad and other unpictured keys still appear in the log.
Reading the result
Hold three ordinary keys and release them one by one. A maximum count of three means three were reported together here. Reserved shortcuts, focus changes and mapping can hide events, so this is not a certified NKRO rating.
Why results can differ
A browser observes events exposed by your operating system. One test cannot establish whether a device is faulty. Connection, settings, focus and browser behavior can change the results.