Tap when the panel turns green — measure your reflexes in milliseconds
For entertainment and informal self-checks only. Reaction time varies with device latency, tiredness and input method — it is not a medical or cognitive assessment.
This test measures visual reaction time: the delay between the panel turning green and your tap registering. A random 1.5–4 second wait stops you from rhythm-guessing the switch, and false starts (tapping while it is still red) are detected and excluded. Everything runs locally in your browser with JavaScript timing — no data leaves your device.
Average human visual reaction time is around 250 ms. Trained gamers and athletes often land between 150–220 ms, while anything under 200 ms is genuinely fast. Touchscreens add 20–70 ms of input latency compared to a mouse, so compare like-for-like devices when bragging to friends.
Use your dominant hand, keep the device flat on a desk, and stay relaxed — tension slows you down. Run the 5-attempt challenge and judge yourself on the average rather than a single lucky tap. If you keep seeing "Too soon!", slow down: anticipating the green actually costs more time than reacting calmly.