⚡ Reaction Time Test
When the red box turns green, click as fast as you can. Five trials give your average and best reaction time in milliseconds.
How the reaction time test works
Reaction time is the gap between a stimulus appearing and your response to it. This test measures simple visual reaction time: the box waits a random amount of time (so you cannot anticipate it), turns green, and records the milliseconds until you click or tap. It runs five trials and reports your average and your best, discarding any false start where you clicked before the colour changed. The timing uses the browser's high-resolution clock, so it is accurate to well under a millisecond; the small, unavoidable overhead is your display's refresh rate and input latency, which affect everyone equally.
A typical result includes your screen and mouse/touch latency, so the absolute number is best used to compare yourself against yourself over time, rather than as a lab-grade measurement. Clicking before green is a false start and does not count, guessing the timing does not help.
Frequently asked questions
What is the average human reaction time?
For a simple visual reaction (click when you see a colour change), the average is roughly 200–250 milliseconds. Reactions to sound are slightly faster, around 150–200 ms, and touch is in a similar range. Anything consistently under about 200 ms for a visual test is quick.
What is a good reaction time?
Around 250 ms is average, 200–220 ms is good, and consistently under 200 ms is fast. Elite athletes and competitive gamers often average in the 150–200 ms range on simple reaction tasks. Consistency across trials matters as much as a single quick result.
Why is my reaction time slower than I expect?
The number includes more than your brain and muscles: your monitor's refresh rate, the mouse or touchscreen's input lag, and the browser all add a few milliseconds each. These are the same for every click, so the test is still a fair way to track your own improvement or compare trials.
What affects reaction time?
Alertness, fatigue, caffeine, age, and whether you were anticipating the signal all matter. Reaction time tends to be fastest in early adulthood and slows gradually with age. Being warmed up and focused on the box, rather than distracted, gives your truest result.
Does clicking early help?
No. If you click before the box turns green it counts as a false start and that trial is voided, so you cannot game the test by anticipating. The test deliberately randomises the delay to prevent guessing.
Is anything uploaded?
No. The timing and scoring happen entirely in your browser; nothing about your results leaves your device.