What is a good reaction time?
Reaction time is the gap between something happening and you responding to it: the light turning green and your finger pressing the button. On a simple online test most people score between 200 and 300 milliseconds, and around 250 ms is typical. That's a quarter of a second, and most of it is your brain at work rather than your muscles.
This guide explains what those numbers mean, why your score changes from day to day and device to device, and what you can do to get faster.
Typical scores
On the reaction time test on this site, which averages five tries, scores roughly break down like this:
- Under 200 ms: very fast, around the top 5% of people.
- 200 to 250 ms: faster than average.
- 250 to 300 ms: average for most adults on a computer.
- 300 to 350 ms: a little slower than average, often because of the device.
- Over 350 ms: slow, usually because of a phone, a wireless mouse, tiredness or distraction.
What happens in those 250 milliseconds
Light from the screen reaches your eye almost instantly, but turning it into a decision takes time. The retina converts light into nerve signals, the visual areas of the brain recognise the change, a decision is made to respond, and a signal travels down to the muscles in your finger. The nerve signals themselves are fast; most of the delay comes from processing in the brain.
That's why simple reaction time, where you respond to one known signal, is faster than choice reaction time, where you have to decide between options first. Tests like the Stroop test and Go/No-Go add a decision, and scores on those are slower for everyone.
Your device adds delay
Every online reaction test measures you and your equipment together. A typical setup adds 10 to 50 ms: the screen takes time to draw the new frame, the mouse or keyboard takes time to report the click, and the browser takes time to handle it. Touchscreens and many phones add more, often 20 to 60 ms on top of a desktop score.
So compare scores on the same device. A friend who scores 30 ms faster on a gaming monitor isn't necessarily quicker than you on a laptop. A wired mouse and a high refresh rate screen give the most accurate numbers.
Things that change your reaction time
- Age: reaction time gets faster through childhood and the teenage years, is usually quickest in your twenties, and slows gradually after that.
- Sleep: being short of sleep is one of the quickest ways to slow down and to make scores more uneven.
- Practice: scores usually improve over the first 10 to 20 tries as you get used to the test.
- Attention: looking away, thinking about something else or anticipating the change all cost time.
- Caffeine: a moderate amount can make you slightly quicker for a while, especially when tired.
- Time of day: many people are a little faster in the afternoon than first thing in the morning.
How fast can a human react?
Responses under about 100 ms are generally treated as guesses rather than reactions. Athletics uses that figure for false starts: a sprinter who leaves the blocks less than a tenth of a second after the gun is disqualified, because nobody is thought to be able to react that quickly to the sound.
Racing drivers and top esports players typically score around 150 to 200 ms on visual tests. Their advantage in competition comes as much from anticipation, knowing where to look and what's coming, as from raw speed.
How to improve
Raw reaction time is partly fixed, but you can almost always improve your score. Use a wired mouse on a computer, sit comfortably with your finger resting on the button, and look at the centre of the screen rather than the cursor. Do a few warm-up rounds, then compare scores taken at similar times of day. Good sleep makes a bigger difference than most tricks.
For reactions that matter in games and sport, practise the specific task. The aim trainer and F1 lights test each add something to plain reaction time: moving to a target, or waiting through a sequence without jumping the start.