Reaction Time Test
Click as soon as the screen turns green. See your average time across 5 attempts in milliseconds, with early clicks detected.
Use your mouse, click the area, or press Space com a área selecionada. São 5 tentativas; clicar antes do verde não vale.
- 1ª—
- 2ª—
- 3ª—
- 4ª—
- 5ª—
Processed on your device. Nothing you type is sent anywhere.
How to use: Reaction Time Test
- Click the large area (or press the spacebar) to start, then wait for the color to change from red to green.
- As soon as it turns green, click or press the spacebar as fast as you can. Clicking early counts as a false start, and you’ll have to try again.
- After 5 valid attempts, see your average and best time, and share your result.
About this tool
What’s a good reaction time?
A healthy adult’s simple visual reaction time averages between 250 and 300 milliseconds. Under 200 ms is excellent and common among trained athletes and gamers. Fatigue, lack of sleep, alcohol, and distractions can slow your reaction time, and age can have a small effect too.
Some of your score is out of your hands: your mouse or touchscreen, your monitor’s refresh rate (60 Hz can add up to 16 ms), and your browser all add a few milliseconds. Compare results using the same device.
How we measure reaction time
The wait before the screen turns green is randomized between 1.5 and 5 seconds, so you can’t predict it. The timer starts on the frame when green appears on the screen and stops the moment you click or tap (using your browser’s high-precision clock). Responses under 100 ms are physically unlikely and count as false starts.
Want to test another skill? See how many numbers you can remember with the memory test, or check your typing speed.
Frequently asked questions
Why is my reaction time slower on my phone than on my computer?
Touchscreens and some mobile browsers add a few milliseconds between your tap and the event reaching the page. Compare results using the same device.
What happens if I click before it turns green?
The attempt is marked as a false start, isn’t included in your average, and is repeated. This keeps you from improving your result by guessing the right moment.
Can I train to improve my reaction time?
A little. Getting enough sleep, focusing on the screen, and practicing can shave off a few milliseconds, but there’s a physical limit: the signal has to travel from your eyes to your brain and from your brain to your hand.
Is it really free? Is there a daily limit?
It's free with no daily limits. Processing happens on your device, so there's no per-use cost and no need to limit you.
Does it work on phones?
Yes. The site works in any modern browser on Android, iPhone, Windows, Mac, and Linux—no installation needed.
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