Average Reaction Time: What’s Normal and What Changes It

The average reaction time for a simple visual signal is about 250 milliseconds, a quarter of a second. Lab studies on healthy young adults often report closer to 200 ms, while online tests usually show 250 to 280 ms because the screen, mouse and browser add delay. This guide explains what is measured, what changes it, and what you can realistically do about it.

What reaction time actually measures

Reaction time is the gap between a stimulus and your response. In that fraction of a second your eyes pick up the change, the signal travels to the brain, the brain decides to act, and a command travels to your finger. Researchers call this simple reaction time when there is one signal and one response. If you must choose between signals, it is called choice reaction time and it is longer.

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Average reaction time by signal

Signal	Typical time
Touch	about 150 ms
Sound	about 170 ms
Sight	about 200 to 250 ms
Sight with a choice to make	350 ms or more

Sight is slowest because the eye needs time to turn light into a nerve signal. That is why sprint starts use a gun, a sound, instead of a flag.

What slows you down

• Tiredness. Lack of sleep is one of the biggest known effects and can add tens of milliseconds.
• Age. Reaction time is usually fastest in the twenties and lengthens slowly after that.
• Distraction. Half your attention elsewhere costs you time on every round.
• Your device. A 60 Hz screen can delay the green frame by up to 16 ms, and a wireless mouse or touch screen adds more.

How to get a more accurate result

1. Use the same device and mouse each time you compare.
2. Run at least five rounds and read the average, not the best single time.
3. Test when rested and without music or notifications.
4. Ignore rounds with a false start; the test repeats them for you.

Can you train it?

Only to a point. Practice removes hesitation and helps you settle on a steady rhythm, and most people improve by a few percent in the first few sessions. After that, gains flatten. Action games train attention and decision speed more than raw reflex.

Frequently asked questions

Is 250 ms a good reaction time?

Yes. It is right at the typical value for a healthy adult on a normal computer.

Who has the fastest reaction time?

Athletes in sprinting and racing sports and some esports players average under 200 ms on a simple test. Sprint rules treat anything under 100 ms as a false start, because that is too fast to be a reaction at all.

Does caffeine help?

It can make you more alert, which helps a little when you are tired. It will not push a rested person past their natural limit.

Why is my phone slower than my computer?

Touch screens have more input delay than a wired mouse, and phone browsers add some of their own.

Summary

Expect roughly 250 ms for a typical visual test, a little less in a lab and a little more on slow hardware. Try the reaction time test for yourself, use the average of several rounds, and keep the same setup if you want to track progress. For background reading, see this overview of mental chronometry.