Reaction Time Test
Click the box the moment it turns green. Your reaction time is measured in milliseconds over 5 attempts, then averaged and ranked against typical human performance.
How It Works
The test has four phases per attempt:
1. Idle — you click the grey box to arm the test.
2. Waiting — the box turns red and displays "Wait…". A random delay between 1 000 ms and 4 000 ms is chosen using setTimeout.
3. Go — the box turns green and performance.now() records the start time.
4. Clicked — you click the green box and performance.now() records the end time. Reaction time = end − start.
Using performance.now() instead of Date.now() provides sub-millisecond precision regardless of system clock adjustments.
If you click during the red "Wait…" phase (a false start), that attempt is invalidated and restarted. This prevents cheating by clicking rapidly before the green appears.
After 5 valid attempts, the tool shows your average, best, and worst time, plus a ranking: Excellent (<150 ms), Good (150–250 ms), Average (250–350 ms), Below Average (>350 ms). The average for a healthy adult is approximately 250 ms.
Frequently Asked Questions
What is a normal reaction time?
A healthy adult averages about 250 milliseconds for a simple visual stimulus. Athletes and gamers who train their reflexes regularly often achieve 150–220 ms. Reaction time naturally slows after age 24 and can be affected by fatigue, caffeine, and attentiveness.
Can I cheat by clicking before it turns green?
If you click during the red "Wait…" phase the attempt is flagged as a false start, your result is discarded, and you have to repeat that attempt. The random delay (1–4 seconds) makes anticipation very difficult to time accurately.
Is mouse reaction time the same as keyboard or touch?
Not exactly. Mouse clicks, keyboard presses, and touchscreen taps each have slightly different physical mechanics and input latency. For the fairest comparison, use the same input method across all your attempts.