Reaction time test
Wait for the box to change, then click as fast as you can. Five tries, then your average.Wait for the box to change, then tap as fast as you can. Five tries, then your average.
About 1 minute · 5 tries · Saved only if you choose
Private by design: your answers never leave this page.
What does it mean?
What can change it?
Sleep, alertness, practice and age all play a part. So does your device: screens and mice can add tens of milliseconds before your brain is even involved.
These bands are our own guide to help you read your result. They're not compared with a population, and they're not a diagnosis.
Save this result on this device to build your report. It stays in your browser. We never receive it.
Challenge a friend.
Send your score as an image. No account, and your result is never uploaded to us.
What’s happening in this test?
Wait. The box sits still, then changes after a random pause, so you can't guess when.
React. When it turns light teal, click or tap as fast as you can. The other modes use a beep, race lights going out, or the spacebar instead.
Five tries. Each try is timed from the change to your press. If you press before the change, or less than 100 ms after it, that try doesn't count and you go again.
Your average. The five times are averaged. First tries are often slower while you learn the task, so look at the pattern too.
What can change your result: your screen and device, how rested you are, and whether you were ready. A different setup can give a different number.
Read more: What a reaction time test really measures
Questions
What is reaction time?
The time between noticing a signal and responding to it: here, between the box changing and your click.
What is the average reaction time?
Browser tests often measure between 200 and 300 ms, but times vary with your screen, mouse or phone, and how alert you feel.
What is a good reaction time?
Under 250 ms is quick; under 200 ms is very fast.
Why is my reaction time so slow?
The usual reasons are tiredness, distraction, a phone touchscreen, or a slow monitor or mouse.
How can I improve my reaction time?
Sleep well, warm up with a few tries, stay focused, and practise. For gaming, a fast mouse and a high-refresh monitor help most.
Does being tired slow your reaction time?
Yes. Lack of sleep is one of the most reliable ways to slow down.
Does caffeine help?
Some studies find a small improvement in alertness and reaction time, especially when you're tired.
At what age is reaction time fastest?
Usually in the late teens and twenties. It slows gradually after that.
What's the difference between a reaction and a reflex?
A reflex (like the knee-jerk) happens automatically without a decision. A reaction needs your brain to notice and decide, so it's slower.
What's the difference between simple and choice reaction time?
Simple = one signal, one response (this test). Choice = several possible signals and responses, which takes longer.
Why don't times under 100 ms count?
Humans can't really react that fast to a signal, so it's a lucky guess. Sprint races use the same idea: a start under 0.1 seconds counts as a false start.
Why is sound faster than sight?
Many studies find people react slightly faster to sounds than to lights.
Is this a medical test?
No. It's for curiosity and self-reflection, not a diagnosis.
Learn more: What a reaction time test really measures
Sources
- Woods, D. L., et al. (2015). Factors influencing the latency of simple reaction time. Frontiers in Human Neuroscience.
- Jain, A., et al. (2015). A comparative study of visual and auditory reaction times. International Journal of Applied and Basic Medical Research.