⚡ Reaction Time Tester
The screen turns green at a random moment — click as fast as you can the instant it does, and your reaction time is measured in milliseconds. Try a few rounds to track your best time and average.
How to use
- Click the area to start.
- Wait while the screen is red — don't click yet.
- Click as fast as possible the instant it turns green to see your reaction time.
How the calculation works
After you start, the screen turns green after a random 1.5 to 4.5 seconds. Click (or tap) as soon as it turns green to see your reaction time in milliseconds. Timing uses the browser’s precise clock (performance.now). The wait is random each time so you cannot anticipate it. Clicking before the screen turns green counts as “too soon” and is not recorded. The average and best of your last 10 attempts are shown.
Worked example
Rough guide (computer with a mouse) Under 150 ms: very fast 200–250 ms: average 300 ms or more: on the slow side (tiredness and sleepiness count) Averaging five attempts smooths out the variation and gives a truer picture.
Things to be aware of
- Display lag (tens of milliseconds) and mouse or touchscreen latency are included, so results from different devices are not directly comparable.
- Touch input on phones can read tens of milliseconds slower than a mouse.
- Reaction times improve when you are focused and warmed up.
FAQ
What happens if I click too early?
If you click before the screen turns green, it shows "too soon" and that attempt isn't counted. Wait for green, then click again.
What's an average human reaction time?
Simple visual reaction time is typically around 200-300 milliseconds on average, though your measured result also depends on display response time and input device latency.
Can I reset my recorded results?
Currently, only the most recent 10 attempts are kept automatically. Reloading the page resets your history.