How the test works
Click the box or press Space to start. The box turns red, then after a random wait it turns green. Click the moment you see green. Click too early and the try does not count. After five tries you get your average and your fastest time.
The Sound mode plays a beep instead of a colour change. The F1 start lights mode copies a Formula 1 start: five red lights come on one by one, and you react when they all go out.
What is a good reaction time?
| Average | Visual | Sound |
|---|---|---|
| Exceptional | Under 180 ms | Under 140 ms |
| Fast | 180 to 230 ms | 140 to 180 ms |
| Normal | 230 to 300 ms | 180 to 230 ms |
| Slower than average | Over 300 ms | Over 230 ms |
Most people react to sound faster than to light, because the ear reaches the brain faster than the eye does. Online tests like this one usually measure a little slower than lab tests, since the screen and mouse add delay.
Why your score includes your hardware
The time you see is your reaction plus the delay of your setup. A 60 Hz screen can show the signal up to 16 ms late, a wireless mouse may add a few milliseconds, and some TVs in picture mode add 50 ms or more. For your best score use a wired mouse, a high refresh monitor if you have one, and close other heavy apps. Test the screen with the refresh rate test and the mouse with the polling rate test.
How to improve your reaction time
- Sleep well. Tiredness is the biggest cause of slow reactions.
- Warm up with a few rounds before you compare scores.
- Keep your finger resting on the button, so you only need to press.
- Look at the centre of the box rather than around the page.
Frequently asked questions
Short answers to the questions people ask most about this test.
What is the average human reaction time?
For a visual signal most people land between 200 and 300 ms on an online test, with around 250 ms as a typical average. Reactions to sound are usually 30 to 50 ms faster.
Why is my reaction time different every time?
Reaction time varies by tens of milliseconds from try to try. That is why the test uses the average of five tries.
Does my monitor affect the result?
Yes. A 60 Hz screen adds up to 16 ms, and slow screens or TVs can add much more. A high refresh monitor and a wired mouse give the most accurate result.
Is my best score saved?
Your best average is saved in your browser on this device only. It is not uploaded anywhere.