Reaction Time Test

Click start, wait for green, then click as fast as you can. The test records your time in milliseconds and tracks your best and rolling average so you can see if you’re warming up or fading. It works on desktop and mobile, and nothing leaves your device.

What counts as fast

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The average focused adult clicks around 250 ms on a simple visual reaction task — normative studies put most healthy adults in the 200–300 ms range. Here’s a rough scale:

• Under 180 ms — elite
• 180–220 ms — excellent
• 220–270 ms — solid / average
• 270–330 ms — a bit slow (tired or distracted)
• Over 330 ms — sluggish, or something is adding lag

What’s actually happening in those milliseconds

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A “simple reaction” — one signal, one response — isn’t a single event. Light hits your retina, the signal travels to the visual cortex, your brain recognizes the change and commands a movement, and the signal runs back down to the muscles in your hand. Each stage costs time, which is why there’s a hard floor: even elite athletes rarely beat ~150 ms, because you can’t out-train nerve conduction speed. Anything under about 100 ms on a test like this isn’t reaction — it’s anticipation (you clicked early and got lucky), which is why good tests penalize jumping the gun.

That also explains the day-to-day swing. Fatigue, caffeine, alertness, and even the time of day shift your average by tens of milliseconds, so a single slow click means little — your best of five on a rested morning is the honest number.

The part that isn’t you

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A surprising chunk of “your” reaction time can be hardware lag. A 60 Hz monitor can add ~16 ms versus a 144 Hz+ panel, and a high-latency wireless mouse adds more. Your click has to wait for the next screen refresh to even see green, then wait again for the input to register — latency that no amount of practice removes. If you care about the last few milliseconds — gaming, editing, anything timing-sensitive — a high-refresh monitor and a responsive mouse are the only fix.

How to get a fair reading

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• Warm up. Your first click of a session is almost always your slowest.
• Take five. Average several attempts; ignore the outliers on both ends.
• Same conditions. Compare morning-to-morning, same device — not a rested desktop score against a tired phone one.
• Rest first. Testing when sleep-deprived measures your fatigue, not your reflexes.

Test a few times when rested for a fair read — your best of five is far more representative than any single click.

Frequently asked questions

What is a good reaction time?

For a simple visual click test, most focused adults land around 250 ms. Under ~220 ms is fast, under ~180 ms is exceptional, and 270–330 ms is normal when you're a little tired or distracted. Reaction time naturally varies by age, alertness, and how rested you are.

How is reaction time measured here?

After you start, the screen waits a random moment, then turns green. The test records the time between green appearing and your click, in milliseconds, using your browser's high-resolution timer. It runs entirely on your device — nothing is uploaded.

Why is my reaction time slower than I expected?

A few things add latency that isn't 'you': a low-refresh-rate monitor, a high-latency wireless mouse, browser load, or simple fatigue. Try again when rested, and note that display and input lag can add 20–50 ms on their own.

Does reaction time get slower with age?

Gradually, yes. Simple reaction time is quickest in your late teens to twenties and slows slowly from there as nerve conduction and processing speed change. The effect is real but modest for everyday tasks, and staying rested, alert, and physically active blunts a lot of it.

Can I improve my reaction time?

Somewhat. Sleep, alertness, and warming up help most. Removing hardware lag — a higher-refresh monitor and a responsive mouse — shaves off the part that isn't physiological. Beyond that, consistent practice produces small gains.