Reaction Time Test
Click when the screen turns green — and don't fall for the distractor colors. 20 rounds measure your average visual reaction time in milliseconds.
What this test measures
Simple visual reaction time: the delay between a visual stimulus (the screen turning green) and your motor response (the click). It is one of the oldest paradigms in experimental psychology, used since Donders' pioneering work in 1868. The test runs 20 rounds — the first 2 are unscored practice, and from round 6 distractor colors flash to punish anticipation. Your score is the average of the scored rounds; early clicks and distractor clicks are rejected so the result reflects true stimulus-driven responses.
The science behind it
The largest public dataset comes from humanbenchmark.com — over 81 million clicks with a median of 273ms, formally analyzed in Bridges et al. 2020 (PeerJ, 'The timing mega-study'). Laboratory studies report simple visual reaction times of 200-300ms for young adults, slowing with age by roughly 2-6ms per decade (Deary, Liewald & Nissan 2011, Behavior Research Methods). Meta-analyses of action video game players show a consistent speed advantage of about 10-12% over non-gamers without loss of accuracy (Dye, Green & Bavelier 2009, Current Directions in Psychological Science). Note that displays and input devices add 20-50ms of hardware latency, which is why online scores run slower than lab-grade photodiode measurements.
How to improve your reaction time
Reaction time is partly trainable. Controlled studies show action video game training transfers to faster responses on unrelated tasks (Green & Bavelier 2003, Nature). Practical levers: sleep (deprivation slows RT by 10-30ms), caffeine in moderate doses, warming up before measuring, and using a high-refresh-rate display with a wired mouse. Expect diminishing returns — most healthy adults can shave 10-30ms with practice, but genetics and age set the floor.
Frequently Asked Questions
What is a good reaction time?
The median across 81M+ online tests is 273ms (Bridges et al. 2020). Under 240ms puts you in roughly the top 15%; under 210ms is around the top 2-3%. Lab-measured times are typically 20-50ms faster because online tests include display and input latency.
Why is my reaction time slower than in other tests?
Hardware matters: a 60Hz display adds up to 16ms per frame, wireless mice add 5-15ms, and browsers add processing time. Compare scores only within the same device and site. Our percentile is calibrated against the same style of browser-based measurement.
Does age affect reaction time?
Yes. Simple reaction time is fastest in your early 20s and slows by roughly 2-6ms per decade afterward (Deary et al. 2011). The effect is gradual — a healthy 50-year-old typically tests within 20-30ms of their younger self.
Do gamers really have faster reaction times?
On average, yes. Meta-analyses find action video game players respond about 10-12% faster than non-gamers with no accuracy trade-off (Dye, Green & Bavelier 2009). Training studies suggest the games cause part of this difference rather than just attracting fast responders (Green & Bavelier 2003).
Why do early clicks not count?
Clicking before the green signal means you anticipated rather than reacted. Anticipation produces artificially fast times that don't measure your nervous system's true stimulus-response speed, so those rounds are discarded and restarted.
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