Accuracy and Disclaimer
Last updated 2026-08-24.
Use the results, but check them
ReactionTimeChart is built to be accurate and its timing is checked against known frame intervals and its statistics against hand-computed distributions. It is still software written by people, running in a browser we do not control, on input we cannot see. Treat every result as a well-informed starting point rather than an authority.
A score here is a measurement of one moment on one device, and the single thing not to do with it is treat it as information about your health, your attention or your ability. It is not, it cannot be, and no arrangement of these charts will make it so.
Specific limits of this site
Nothing on this site is a medical, psychological or diagnostic test. The tests here are general-interest measurements taken through a web browser, and no score, chart or percentile on this site says anything about attention, cognition, neurological health or any medical condition. If you are concerned about your reaction time or your memory, that is a conversation for a qualified clinician and not for a web page.
A reaction time measured in a browser includes your display and your input device as well as you. The site estimates that contribution from your own measured refresh rate and prints it beside your score rather than folding it in silently, and the method is written out in full on the “How we measure” page.
The error margin shown with a score is calculated from the display refresh interval and the input device’s polling interval, combined in quadrature and reduced by the number of rounds averaged. It does not cover panel response time, compositor buffering or wireless input latency, because a web page cannot observe those.
Charts are drawn only from results actually recorded on this site, and each one states the number of attempts behind it. Below a threshold of two hundred attempts for a given test and input method, no curve is drawn at all and the chart says so.
No chart on this site is ever drawn from invented, modelled or simulated data. Synthetic results are used during development and are excluded from anything published.
Where a page cites published research for an age comparison, the source is named inline. Laboratory studies use dedicated response hardware and their figures are not directly interchangeable with a browser measurement, which the pages that cite them say.
Results are submitted anonymously and cannot be traced back to you, which also means we cannot delete or retrieve an individual result on request. Your own attempt history is kept only in your browser.
Not professional advice
Nothing on this site is medical, psychological, diagnostic or other professional advice, and using the set of reaction and memory tests does not create a professional relationship of any kind. If a decision has real consequences, ask somebody qualified and accountable.
Liability
Our liability for the results this site produces is limited as described in the Terms of Service. In short: the site is free, it is provided as-is, and we cannot accept responsibility for losses caused by relying on it without checking.