Reaction Time Test
Wait for green, click as fast as you can, five times. You get your median rather than a single lucky round, your full history is kept in this browser, and there is no account to create.
- Free forever
- No sign-up
- Never leaves your device
Five rounds. Wait for green, then click or press space as fast as you can. Clicking early repeats the round.
Your history
At a glance
- Price
- Free, with no usage limit
- Account
- Not required
- Watermark
- None
- Your data
- Processed entirely in your browser and never uploaded
- Works on
- Any modern browser, desktop or mobile
What the number actually means
A visual reaction time is the gap between a change appearing on your screen and your finger completing a click. Most adults land between 200 and 300 milliseconds, and a median around 250ms is unremarkable. Under 200ms is genuinely fast.
That range is smaller than it sounds. The difference between a good day and a tired one is routinely 30 to 40 milliseconds, which is most of the gap between "average" and "fast" — so a single result tells you very little, and the point of five rounds is to stop one lucky click from flattering you.
Why the median and not the average
One distracted round at 600ms moves a five-round average by 70 milliseconds. It moves the median by nothing at all. Since a lapse of attention is not what anyone means by "my reaction time", the median is shown first and the mean second.
This is the same reason the test repeats a round when you click early rather than scoring it. An anticipated click can come in at 80ms, which is faster than a human nerve signal can travel, and averaging it in would produce a number that is not a reaction time at all.
What is in the number besides you
| Source | Typical delay | Notes |
|---|---|---|
| Display refresh | 0–16 ms | On a 60Hz screen. A 144Hz panel cuts this to under 7ms. |
| Wireless mouse or trackpad | 2–10 ms | Wired peripherals are usually faster and more consistent. |
| Browser and OS scheduling | 1–5 ms | Worse with many tabs open or a busy machine. |
| Touchscreen | 20–80 ms | Substantially slower than a mouse. Phone results are not comparable. |
Added up, your equipment can account for 40 milliseconds or more before your nervous system is involved at all. That is why this test compares you against your own history rather than a global table — the only fair comparison is you, yesterday, on the same machine.
What actually changes it
Sleep is the largest single factor, and it moves reaction time further than almost anything else you can control. Caffeine produces a modest improvement, mostly by offsetting tiredness rather than by making a rested person faster. Practice helps for the first few dozen attempts and then plateaus quickly — you are learning the task, not rebuilding your reflexes.
Age matters too, gradually: reaction time is typically fastest in the early twenties and slows slowly after that. The effect across a decade is smaller than the effect of one bad night's sleep, which is worth keeping in proportion.
What this test is not
It is not a medical or diagnostic instrument. A slow result means you were slow on this machine on this day, and nothing more. Reaction time is genuinely used in clinical and sports settings, but with calibrated hardware and controlled conditions that a web page cannot reproduce.
If you want a fair comparison, take it at the same time of day on the same device, and look at the trend across a fortnight rather than at any single number. Your history strip above is there for exactly that.
Frequently asked questions
What is a good reaction time?
Most people land between 200 and 300 milliseconds on a visual click test, and around 250ms is a typical median for an adult. Anything under 200ms is fast. The number is heavily affected by your input device, your screen refresh rate and how tired you are, so compare yourself against your own history rather than against a table.
Why does the test use a median rather than an average?
Because one accidental early click or one moment of distraction can move an average by 50 milliseconds and tells you nothing about your reflexes. The median ignores those outliers, which is why it is the figure shown first.
Does my monitor affect the result?
Yes, and more than most people expect. A 60Hz display adds up to about 16 milliseconds of delay before a change is even drawn, and wireless peripherals add a few more. This measures your reaction plus your hardware, so results are only comparable on the same setup.
Is my history saved anywhere I have to sign in for?
No. There is no account and no server. Every attempt is stored in your own browser using local storage, which means it stays on this device and we cannot see it. Clearing your browsing data clears it, so export it first if you want to keep it.
What happens if I click too early?
The round is discarded and repeated, and the early click is recorded separately rather than silently ignored. Anticipating the signal is a real and measurable habit, so it is more useful to see how often you do it than to have it hidden.