Reflex test
How fast are your reflexes? Tap to arm this panel → it holds red → the instant it turns green, tap. Five rounds, averaged in milliseconds, then read against published laboratory figures. Nothing is uploaded: your scores stay in this browser.
Tap to start
5 rounds · random 1.5–4.5 second wait each time
How to read it: the clock runs from the frame that paints green to your first tap, so a lower number is a faster reflex. What you are measuring is a simple visual reaction — see one thing, make one movement.
Band · Finish 5 rounds to get a band
How the reflex test works
One stimulus, one response. The panel holds red for a random 1.5 to 4.5 seconds, then turns green; the clock starts on the frame that paints green and stops at your first tap, timed to the millisecond. Five rounds are averaged, because one lucky tap is noise and one tired tap is noise too.
Three kinds of round are thrown out rather than scored: a tap before green (a false start), a tab or window switched mid-wait, and a wait that runs long because the browser throttled a background timer. A tap that lands late is kept — the panel genuinely was green that long, so that is a slow reaction, not a broken measurement.
This is the same instrument as the reaction time test, running the same engine with the same void rules, on this page's own address. What it leaves off is the age comparison panel and the history chart, which live on the main test.
Reflex test vs reaction time test
In ordinary English the two are the same request. In the laboratory literature they are not quite: a true reflex — the knee-jerk arc — travels through the spinal cord and never reaches the brain, which is why no screen can measure it. There is no picture you could show that would produce it, and no button you could press that would record it.
What people mean when they search for a reflex test is a simple visual reaction time test: see green, move, as fast as you can. That is what runs above, so a reflex time and a reaction time measured here are the same number. The difference is only which word the page is built around.
What's a normal reflex time?
There is no separate published dataset of browser reflex times — every figure this site prints is simple visual reaction time, measured in a laboratory or tapped into this panel. On a screen, most adults land between about 255 and 280 ms; under 250 ms is a quick hand, and under 200 ms on a browser is uncommon.
The laboratory reference underneath those browser numbers is a whole-sample mean of 231.0 ms: 217.9 ms for 18–24 year-olds rising to 239.1 ms for the 59–65 group, measured in Woods et al. (2015) — 1,469 adults, 120 trials each, on a laboratory rig. Ages outside 18–65 get no figure at all, because that study measured none.
Where your own number sits against those bands is set out on the normal reaction time page.
Reflex time by age and device
Age moves the reflex number slowly: about 0.55 ms per year, which is 21 ms between the youngest and oldest group the study measured. Your device moves it faster. Display refresh, touch sampling and the operating system's input path add a disclosed 20–60 ms to every score before you are involved at all.
So a 260 ms reflex on a 144 Hz desktop and 260 ms on a budget phone are not the same hand, and comparing two people's raw milliseconds across different hardware is not a fair test. The full breakdown of both effects is on average reaction time by age and device.
Can you train your reflexes?
Partly, and by less than the games industry implies. Sleep, warmth, caffeine and familiarity with the task all move the number, and practice helps most in the first few sessions; the realistic ceiling on raw simple reaction time is modest. The larger gains in actual play come from prediction — starting the movement before the stimulus is complete — which this test deliberately does not measure, because it asks you to react rather than to guess.
Nothing on this page is a claim about your nervous system. How every figure is computed, and what it cannot tell you, is written out on the methodology page.
Frequently asked
- What is a reflex test?
- One stimulus, one response: the panel holds red for a random 1.5–4.5 seconds, turns green, and your first tap stops the clock. Research calls this simple reaction time. A true spinal reflex cannot be measured on a screen at all.
- Is 200 ms a good reflex?
- On a browser, yes — that is fast. Take the disclosed 20–60 ms of screen and input path back off and you are at roughly 140–180 ms on the laboratory scale, under the 217.9 ms mean measured for 18–24 year-olds.
- Are my reflex scores uploaded anywhere?
- No. There is no backend, no account and no analytics, so there is nowhere for a score to travel. Results sit in your browser's localStorage and clearing site data deletes them.