What is reaction time — milliseconds to a stimulus
What reaction time is: milliseconds from a visual cue to a click, typical ranges, and an online test.
Reaction time here is the gap between a clear visual change (the pad turning green) and your click or keypress. The browser stamps the clock after that paint, then again on the pointer-down or Space.
Simple visual-click tasks often land near 200–250 ms for adults. Anticipation looks faster until a false start catches it. Sleep, caffeine, display lag and a heavy mouse all move the number.
ToolsHelper runs the check in the tab: random wait, green flash or beep, milliseconds, plus official five and input compare. It is not a lab chronometer — monitor and OS delay are in the figure.
A simple visual reaction time for a practiced adult is often around 200–250 ms. Under 100 ms on a click test is usually an early click, not a fast nerve. Sound can be a little faster than a light on the same test. Fatigue, a small button, and a busy page all add delay that is not your reflex. This page defines the measurement. The reaction tool runs the trials and discards the false starts.
FAQ
Why not show a countdown?
A countdown lets you guess the beat. A random wait measures the green, not the rhythm.
Keyboard or mouse — which is faster?
Whichever device you already use. The test accepts click, tap and Space; compare with the same input.