Reaction Time Test
Measure how fast you react to a color change, averaged over five tries. Your work stays on this device whenever possible.
How to use Reaction Time Test
- Click the blue box (or press Space) to start.
- Wait while it is red; clicking now shows "Too soon".
- Click the moment it turns green; your time appears in milliseconds.
- Repeat until five tries are done to get your round average.
- Click again to start a new round and try to beat your best.
Worked example
Start a round and react to five green screens: 243, 231, 256, 219 and 238 ms. The page shows your last time, a round average of 237 ms and a best of 219 ms, and the table lists all five tries.
When to use this tool
- A quick focus or alertness check before gaming or driving practice.
- A classroom experiment comparing reaction times between students.
Important limitations
Screen refresh, input lag and mouse latency add roughly 10-50 ms that a web page cannot remove, so compare results on the same device.
Frequently asked questions
What is a good reaction time?
Most people land between about 200 and 300 ms on a visual test like this, and practiced players often get close to 150-200 ms. Results depend on your screen, mouse and how alert you are, so compare against your own earlier scores.
Why is the wait random?
A fixed delay lets you anticipate the change. The delay is drawn at random between 1.5 and 4.5 seconds, so the only way to score well is to react to the color change.
Does my screen affect the result?
Yes. Monitor refresh rate, input lag and mouse latency add roughly 10-50 ms that no web page can remove. A 144 Hz gaming monitor will usually give lower times than a 60 Hz laptop screen.
Why average five tries?
Single attempts vary a lot. The average of five smooths out one lucky or distracted click and gives a more honest measure.
Are my results saved?
The table shows the current round only and clears when you leave the page. Nothing is stored or sent.