Articles · 4 September 2026
Average reaction time by age
Reaction time slows by about half a millisecond a year — and the interesting part is that only half of the response slows at all.
The number
The best controlled measurement of simple visual reaction time comes from a study of roughly 1,500 adults that used dedicated hardware rather than a browser. It found a mean of 231 milliseconds raw, or 213 milliseconds once the measurement hardware’s own latency was subtracted.
Across age groups the means ranged from about 218 to 239 milliseconds, and reaction time slowed by roughly half a millisecond per year of age. That is a real effect and a remarkably orderly one, but over a decade it amounts to five milliseconds — less than the delay your monitor adds.
| Measure | Value |
|---|---|
| Mean, raw | 231 ms |
| Mean, corrected for hardware latency | 213 ms |
| Range across age groups | 218–239 ms |
| Slowing per year of age | ≈ 0.5 ms |
Only half of the response ages
The same study split the response into two parts: the time to detect the stimulus, and the time to initiate the movement. Detection took about 131 milliseconds and stayed essentially constant across the lifespan. Movement initiation was where all the age-related slowing appeared.
That is a more useful fact than a table of averages. Your eyes and visual cortex are not getting slower in any way this test can see. What changes is the motor side — deciding to move and getting the finger to move.
A puzzle worth knowing about
Francis Galton measured reaction times in the 1880s and 1890s and recorded means between 181 and 189 milliseconds — faster than modern laboratory subjects. This has been examined seriously in the literature rather than dismissed, and the leading explanation is that Galton’s pendulum chronometer and a modern computer measure slightly different things, not that Victorians had better reflexes.
It is a good reminder of what this whole site is about. A reaction time is a measurement of a person plus their equipment, and the equipment has never been constant.
Why a web test reads slower than a laboratory one
Every browser-based test inherits whatever monitor, mouse and operating system the participant happens to own. A 60 Hz screen adds up to 16.7 milliseconds of quantisation before anything else, a wireless mouse polling at 125 Hz adds up to 8 more, and display processing adds more on top.
That is why we measure and report your display’s refresh rate next to your score, and why our timing starts at the frame the browser actually painted rather than at the moment our code asked for the change. It reads slower than sites that do not do this, and it is the honest number.
Sources
- Woods, Wyma, Yund, Herron & Reed (2015), Frontiers in Human Neuroscience — Factors influencing the latency of simple reaction time. About 1,500 adults, dedicated hardware; mean 231 ms raw, 213 ms corrected; ≈0.5 ms slowing per year; detection ≈131 ms and age-invariant.
- Human Benchmark reaction time statistics — Reports a median of 273 ms across more than 81 million recorded clicks — a web population on uncontrolled hardware, which is why it sits well above the laboratory figure.