What we do
Reaction Time Test is a small collection of online brain and reflex tests. Each one is designed around a single, well-understood cognitive measure:
- Reaction Time Test: simple visual reaction time, measured in milliseconds across five attempts.
- Ball Catch Challenge: anticipatory timing and precision under speed pressure.
- Number Memory Test: digit span, measured with a sub-second flash so it taxes raw encoding rather than rehearsal.
How we measure reaction time
The timer starts on the frame the screen actually paints green. We use
requestAnimationFrame so the timestamp is taken after the paint, not when
the colour change was requested. It stops on your click or spacebar press. The delay
before green is randomised between 1.2 and 4.2 seconds, so anticipation can't be used
to game the result; an early click is recorded as a false start.
Five attempts are averaged, because a single attempt is noisy. Your hardware matters too: a 60 Hz display adds up to roughly 16 ms of latency, and some TVs add far more. Compare your score against your own history first, and against population averages second.
Where our benchmark numbers come from
The reference figures on this site (a median around 273 ms for simple visual reaction time, and the age-related decline of roughly 1–2 ms per year after the mid-twenties) come from published large-sample work on simple and choice reaction time, including:
- Deary, I. J., & Der, G. (2005). Reaction time, age, and cognitive ability.
- Dykiert, D. et al. (2012). Age differences in intra-individual variability in simple reaction time.
- Woods, D. L. et al. (2015). Age-related slowing in simple visual reaction time.
- Laming, D. (1968). Information theory of choice-reaction times.
Every figure we publish is a population-level approximation, not a clinical threshold.
Accessibility and performance
The site has no frameworks, no trackers, no analytics and no external requests on first paint. Tests work with a mouse, a keyboard, or a touchscreen, and the layout adapts to phones.
Who we are
Reaction Time Test is built by a small team working in AI and brain-computer interface (BCI) research. We spend our days building machine learning models and exploring how brains and computers can work together. This project started as a side experiment: we wanted clean, reliable cognitive tests we could use ourselves, and figured others might find them useful too.
We keep things simple and honest. All benchmark numbers come from published research (see sources above),
not made-up estimates. The tests use requestAnimationFrame for accurate timing and randomize
intervals so you can't game the results. We built these tools for ourselves first, so we care about
getting the details right.
Contact
Found a bug, or want to suggest a test? Reach us at 731103626@qq.com. We read everything, though we can't promise a personal reply.
Disclaimer
All tests are for entertainment and self-knowledge only. They are not medical devices and are not a diagnostic tool of any kind.