When the red box turns green — click as fast as you can. Five rounds, your average, and a rank. How fast are your reflexes?
⚡ Tip: use a mouse, sit close, and don't blink. Scores stay on your device.
FPS and MOBA performance leans on visual reaction speed. Test before and after warming up — the difference is real.
Test before and 30 minutes after coffee. (Sleep deprivation works the other way — dramatically.)
Pass the laptop around — a 5-round average makes it fair, and the best score sticks around to beat.
A simple visual reaction time test measures a chain of events, not a single one. Light reaches the retina, is transduced and transmitted, is processed in the visual cortex, a motor command is generated and travels to the hand, the muscle contracts, and the switch closes. Typical results of 200 to 250 milliseconds are the total of all of it.
The purely biological component is only part of the figure. A substantial share is equipment: the display's refresh rate means the stimulus appears somewhere within a frame interval — 16.7 milliseconds at 60 Hz — and input polling, operating system scheduling and browser event handling each add a few milliseconds of variable delay.
This is why a browser-based test cannot be compared with a laboratory measurement, and why the same person scores differently on different hardware. A 120 Hz screen with a wired mouse genuinely produces better numbers than a 60 Hz screen with a Bluetooth one, with no change in the person.
Average simple visual reaction time for young adults is around 200 to 250 milliseconds, with auditory reaction slightly faster at roughly 140 to 160, because auditory processing has a shorter pathway. Choice reaction time — deciding between responses — is considerably longer, and the increase scales with the number of options in a well-established relationship known as Hick's law.
Reaction time varies within a person far more than most people assume. It is slower when tired, after alcohol, later in the day for some chronotypes, and when attention is divided. It also slows gradually with age from the mid-twenties onward, though the effect over decades is smaller than the variation between individuals.
A single trial is close to meaningless. Take at least five and use the median rather than the mean, which is heavily distorted by one slow trial. Anticipating the stimulus produces artificially fast times that are guesses rather than reactions, which is why good tests randomise the delay and discard responses that arrive impossibly early.
This is a game and a curiosity, not a clinical instrument. Reaction time is used in genuine cognitive assessment, but with calibrated hardware, standardised conditions, many trials and normative data — none of which a browser test has.
It does not measure intelligence, driving ability or fitness to do anything. Real-world driving reaction involves perception, decision and action under divided attention, and published figures of around 1.5 seconds for braking reflect that whole process rather than a simple stimulus-response.
Concern about your reaction time, coordination or cognition — particularly a noticeable change — is a matter for a doctor rather than a web page. A test like this cannot detect or rule out anything, and a slow score here most likely reflects a 60 Hz display and a distracting environment.
Yes — a 60 Hz display adds up to 16 ms versus a 144 Hz one, plus input lag. Compare scores on the same setup.
Sleep, caffeine, time of day and warm-up all shift reaction time by 20–50 ms. It's a fun proxy for alertness.
Usually a mouse: touchscreens add touch-processing delay. Phones typically score 30–60 ms slower than desktops.
Display refresh rate alone introduces up to 16.7 milliseconds of variation at 60 Hz, and wireless input adds more. A faster screen and a wired mouse produce better numbers with no change in you.