Reaction Test — Level 1

Explore your response speed: wait for green, then click. Lower ms reflect more efficient sensorimotor processing.

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Test

Click to start

Click the area above. When it turns green — click as fast as possible.

What reaction time actually measures

Your time in milliseconds combines several stages: light hits the retina, signals travel through the optic nerve, the visual cortex recognizes the change, premotor and motor areas plan a click, and the command runs down the spinal pathways to the hand.

Typical simple RT~200–250 ms

Athletes or highly practiced users can dip below ~180 ms; fatigue or distractions can push you above ~300 ms.

Signal path, step by step

Retina → Optic nerve → Thalamus (LGN) → Visual cortex (V1/V2) to detect the green change, then Parietal / Premotor areas select the response, Motor cortex fires, and the impulse travels via peripheral nerves to finger flexors.

How fast are nerves?

Well-myelinated motor and sensory fibers conduct roughly on the order of tens of meters per second (e.g., ~50–120 m/s for fast fibers). That means pure conduction is quick; the bigger bottleneck is cortical processing and decision initiation.

Why hardware matters

Display latency: LCD/LED pixel response + scanout can add several milliseconds; gaming panels reduce this with high refresh and low overdrive artifacts.

Input lag: Mouse polling (125–1000 Hz) adds ~1–8 ms; wireless gear can add a little more depending on the receiver.

Browser & OS: event scheduling, background load, and power-saving modes introduce jitter. Close heavy tabs for more stable measurements.

Benchmarks & practice tips

Use the same device and lighting for comparable baselines. Take several attempts and look at the trend; single clicks are noisy. Aim to reduce lapses (very slow outliers) rather than chase one-off personal bests.