Reaction Time Test

How to take the reaction time test

1. Sit comfortably with your finger resting on the mouse button, the screen or the Space bar.
2. Click the blue box to start. It turns red: wait, and do not click yet.
3. After a random delay of 1.5 to 5 seconds it turns green. Click, tap or press Space as fast as you can.
4. Your time appears in milliseconds. Click again for the next try. Clicking while it is still red counts as "too soon" and the try is repeated.
5. After 5 tries (or 10) you get your average. Press Reset to start a fresh round.

What the results mean

Your reaction time is the gap between the box turning green and the browser receiving your click. It includes the time your eyes and brain need to notice the change, the time to move your finger, and a small delay from your mouse and screen.

Look at your average, not your best. A single 150 ms try is often a lucky guess that happened to land at the right moment. Times under 100 ms are almost always anticipation, because the eye and brain cannot react that fast.

What affects your reaction time?

Visual reaction time for most healthy adults sits between 200 and 300 milliseconds. It is fastest in your twenties and slows slowly with age, by a few milliseconds per decade. Sleep, caffeine, warm-up and focus matter more than age over a single day: a tired person can easily lose 50 ms.

Your equipment adds delay too. A 60 Hz screen only updates every 16.7 ms, so on average the green appears about 8 ms after the browser draws it. A 144 Hz or 240 Hz monitor cuts that. Wireless mice, Bluetooth keyboards, TV "picture modes" and browser extensions can each add 5 to 30 ms. That is why the same person scores better on a gaming PC than on a phone. Check your display with the refresh rate test, and if you play games, our CPS test measures how fast you can click once you have reacted.

This reaction time test uses the browser's high resolution timer and listens for the earliest input event (pointer down, not the full click), so it adds as little delay as possible.

How to improve your reaction time

Reaction time improves with practice up to a point, mostly because you learn to stay relaxed and focused. Warm up with a few rounds, keep your finger touching the button so it only has to press, look at the center of the box rather than around it, and sit at a comfortable distance. Regular sleep and staying hydrated help more than any trick. Gamers also lower system latency: a wired mouse, a high refresh rate monitor, game mode on the TV and turning off V-Sync in games.

Common problems and fixes

My times are much slower than expected

Close other tabs and apps, plug in a laptop charger (battery saver can slow the browser), and use a wired mouse. On a TV or projector, turn on Game mode, because picture processing can add 50-100 ms.

It always says "too soon"

Wait for the box to turn fully green. The delay is random on purpose, so you cannot predict it. Rest your finger on the button instead of hovering, and press only when you see green.

Pressing Space scrolls the page

Click inside the test box first so it has focus. While the box is focused, Space and Enter are captured by the test and the page does not scroll.

The test feels slow on my phone

Phone screens and touch panels add some delay. Turn off battery saver, raise the screen brightness and tap with your thumb resting just above the screen.