Reaction time test

How to take the reaction time test

1. Click the pad (or press Space or Enter). It turns to Wait for green…
2. Keep your finger ready, but do not click yet. The pad waits a random 2 to 5 seconds, so you cannot learn the rhythm.
3. The moment it turns green and says Click!, click, tap or press Space.
4. Your time appears in ms. Click again for the next attempt. After 5 attempts you get the summary.

Clicked before green? You see Too soon! and that attempt does not count; false starts are listed separately.

The result shows four numbers:

• Average: the mean of your 5 valid attempts.
• Median: the middle value. One slow attempt (you blinked) barely moves it, so it is often the fairest single number.
• Best: your fastest valid attempt.
• Spread (SD): the standard deviation. A small spread means you are consistent; a large one means some attempts were much slower than others.

A chart shows this session and the averages of your recent sessions, saved only in this browser.

What is a good reaction time?

We have no global ranking: your results stay on your device, so we do not know anyone else's scores. For context, here is a published study.

In a large lab study of simple visual reaction time (1,469 adults aged 18 to 65, responding to a stimulus with a mouse click), the mean was 231 ms, or 213 ms after the researchers subtracted the delay of their own screen and mouse. The youngest group averaged about 218 ms (200 ms corrected), and times grew slowly with age, by roughly half a millisecond per year. Source: Woods et al., 2015, Frontiers in Human Neuroscience.

So a median in the 200s on a normal setup is in the range that study measured. Do not read much into 10 or 20 ms differences between devices.

Your device adds delay to the result

Every online reaction test measures you plus your hardware. The time starts when the browser paints the green frame and stops when the click event arrives, and in between there are delays you cannot see:

• Display latency: the screen needs time to show a new frame. A 60 Hz screen draws a frame every 16.7 ms; a 144 Hz screen every 6.9 ms. TVs with heavy picture processing add more.
• Input latency: a mouse, keyboard or touch screen needs a few milliseconds to report your press. Wireless and Bluetooth devices can add more, and phone touch screens are often slower than a wired mouse.
• Browser and system: a busy computer or power-saving mode adds jitter.

In the study above, the screen and mouse alone added 17.8 ms on average, and the authors note that older studies were inflated by up to 100 ms by such delays. That is why we time from the exact frame that turned green, and why you should compare results on the same device. Want to see your own input side? Try the mouse polling rate test or the keyboard polling rate test.

What affects your reaction time

Apart from the device, the biggest factors change from day to day:

• Sleep: tiredness makes you slower and, even more, less consistent. A spread (SD) much bigger than usual often points to sleep.
• Caffeine: coffee can make a tired person a bit quicker, but too much makes you jumpy (more false starts).
• Warm-up and focus: the first attempt is often the slowest. Do one practice session, then measure.
• Expectation: the random delay is there so you react to the green, not to a rhythm. If you get many false starts, you are guessing.
• Age and practice: reaction time slowly increases with age; practice mostly makes you more consistent.

Tips for a fair measurement

- Use the same device and the same input every time. - Sit comfortably, rest your finger on the button, and look at the centre of the pad. - Judge by the median over several sessions, not by one lucky best.

Other ways to test your reflexes

• Ruler drop test: a ruler and a friend, no screen and no device latency.
• Lights out reaction test: react when five red start lights go out.
• Aim trainer: reaction plus mouse precision on 30 targets.
• CPS test and spacebar clicker: pure speed.

All are on the skill tests page. Our guide to reading your test results explains polling rate and refresh rate.