What the score means
CPS means received presses divided by the selected duration in seconds. For example, 32 presses in 5 seconds give 6.4 CPS. The first press counts and starts the window; an event at or after the end does not count. The result settles for 250 ms to include inputs already produced before the end but still waiting to be handled.
The score counts press starts, including a last press held across the finish. Releases permit another press; they do not add to the score. A double-click signal is not an extra input.
Compare the same test
Keep the duration, device, button and gesture the same. Mouse-like input can come from a trackpad; this page does not identify the hardware. The one-finger touch test is separate, so its result should not be presented as mouse clicking speed. Take a break if your hand becomes uncomfortable.
When a round has no score
Hiding the page, leaving the window, cancelling touch, using multiple fingers or leaving the area while holding the mouse interrupts the round. A browser delay over 500 ms or an input delivered more than 250 ms late also invalidates it. Start a new round; an incomplete round is never extrapolated.
The timer uses browser event timestamps and a monotonic clock. Privacy settings may round timestamps. Some browsers use a separate platform clock: intervals remain relative to the first event, and the visible timer starts when it is received. Its initial delivery delay is then unavailable. Results are local observations, not a human-performance certification, anti-cheat verdict or electrical measurement.
Click speed or unwanted double clicks?
A high CPS cannot tell you whether a switch is bouncing. To investigate extra clicks, make slow, intentional single presses in the double-click test.