Reaction Time Test

What is a reaction time test?

A reaction time test measures how quickly you respond to a sudden change — here, how fast you click after the screen turns green. Your result is shown in milliseconds (ms), where lower is better. It is a simple, surprisingly addictive way to see how sharp your reflexes are right now.

The test deliberately waits a random amount of time before turning green, so you can't cheat by clicking on a rhythm. Click too early and it tells you — you have to actually react to the colour change.

How to use it

1. Click Start (the panel above).
2. Wait while it's red — don't click yet.
3. The instant it turns green, click as fast as you can.
4. Your time appears in milliseconds. Your best score is saved so you can try to beat it.
5. Hit Share result to challenge a friend.

If you click while it's still red, you'll get a "Too soon" — just click again to retry.

What counts as a fast reaction?

As a rough guide for a simple click test:

• Below 200 ms — fast, sharp reflexes.
• 200–250 ms — around average for adults.
• 250–300 ms — typical when tired or distracted.
• Above 300 ms — slower today; try again after a short break.

These are approximate. Reaction time isn't fixed — it changes with sleep, caffeine, focus and even time of day.

What affects your reaction time?

• Alertness and sleep. Tiredness slows you down more than almost anything else.
• Your hardware. A high-refresh-rate screen and a low-latency mouse shave off real milliseconds versus a laptop trackpad.
• Anticipation. Staring and bracing can help slightly, but tense over-anticipation leads to "too soon" misclicks.
• Practice. Most people improve a little with a few rounds as they get used to the rhythm of the test.

Can you train your reaction time?

To an extent, yes. Short, regular practice, good sleep and staying relaxed-but-ready all help. The most reliable gains come from removing what slows you down — fatigue, distraction and laggy hardware — rather than chasing a single record-breaking click. If you enjoy putting your hands to the test, an aim trainer sharpens targeting and a click speed test measures how fast you can fire, both of which lean on the same quick reflexes.

The best way to use this test is to take a handful of goes, watch your best and your typical range, then come back another day and see if you can beat it. It only takes a few seconds, runs entirely in your browser, and there's a friend out there who thinks they're faster than you.