About ReactionTime

ReactionTime is a free collection of 21 browser-based tests for reflexes, input speed, hand-eye coordination, memory, attention and perception. The reaction time test is at the heart of it — click the moment the screen turns green and read your result in milliseconds — and everything else grew out of the same idea: quick, honest measurements you can take in seconds without signing up for anything.

What we set out to build

Most online tests of this kind bury a two-second interaction under pop-ups, sign-up walls and pages of filler. We wanted the opposite: a tool that loads fast, works the instant it appears, and tells you something true about your result instead of just showing you a number. That is why every test ships with a benchmark table explaining where your score sits, and an honest note about what your hardware — your screen refresh rate, your mouse, your headphones — contributes to it.

How it works

The whole site is static and runs entirely in your browser. There is no server doing the timing, no account, and nothing to install. Your attempts live in the page while you use it, and only your best score for each test is saved locally on your own device so it survives a reload. Clear your browser storage and it is gone.

What's on the site

The tests are grouped by what they measure — reaction and reflexes, aim and hand-eye, input speed, memory and recall, attention and control, and vision and perception. A few of the most popular:

• Reaction Time Test — the classic click-when-green reflex measurement.
• CPS Test — how many times you can click per second.
• Aim Trainer — pop 30 targets as fast and accurately as you can.
• Typing Speed Test — your words per minute and accuracy.
• Chimp Test — the working-memory test chimpanzees famously beat humans at.

Accuracy and corrections

The timing uses the browser's high-resolution performance clock, which is precise to a fraction of a millisecond. The benchmark ranges are drawn from widely reported figures and are meant as friendly guidance, not clinical assessment — these are fun, informative tools, not medical or diagnostic instruments. If you spot something inaccurate, pleasetell us and we'll fix it.

Privacy in one line

No accounts, and your results stay on your device. For the full details — including how any future analytics or advertising would work — see our Privacy Policy.