Reaction Test
Test your reflexes! Click when the screen turns green.
Wait for green...
Click as soon as the screen turns green!
Last 5 Attempts
Reaction Time Rating
About Reaction Test
This test measures simple reaction time: how long it takes you to respond to a signal you are already expecting. Wait for the colour to change, click as soon as it does, and the result is reported in milliseconds.
What the number means
Typical simple visual reaction time for a healthy adult falls between roughly 200 and 300 milliseconds. Under 200 ms is fast; under 150 ms usually means you anticipated rather than reacted. The figure includes the display's own latency and your input device, so a wired mouse on a high-refresh screen measures faster than a touchscreen — the difference is the equipment, not you.
Why does my score get worse the more I try?
Fatigue and vigilance decrement. Sustained attention to a monotonous signal degrades within minutes, so scores usually drift upward across a long session. Compare like with like: your first five attempts today against your first five attempts another day.
What changes reaction time?
Sleep, caffeine, age, time of day and practice all move it measurably. Sleep loss is the largest everyday factor. Age slows it gradually from the mid-twenties. Practice helps mainly by removing hesitation about the task itself rather than by speeding up the underlying nerve conduction.