Reflex Speed Test

What it measures

This test measures your simple visual reaction time — the interval between a colour change appearing on screen and your finger or hand responding. It is a direct indicator of reflex sharpness, sensorimotor alertness, and how quickly your nervous system can detect and act on a sudden change in your environment.

How it works

A large coloured panel is displayed on screen. It begins red (wait) and switches to green at a random moment between 1.5 and 4 seconds later. You tap or click the panel as fast as possible the instant it turns green. Five trials are recorded; early clicks (before green) are discarded and that trial is repeated. Your average reaction time across all five valid trials is reported in milliseconds, together with your single fastest response.

Tips for an accurate result

• 1Prioritise sleep quality — Sleep deprivation is one of the most potent slowers of reaction time. A single night of poor sleep (under six hours) can lengthen simple RT by 30–60 ms. Consistent, adequate sleep is the single most effective way to keep reflexes sharp over time.
• 2Use caffeine wisely — A moderate caffeine dose (roughly 3–6 mg per kg of body weight, e.g. one to two cups of coffee) taken about an hour before testing can shorten simple reaction time in rested individuals. However, in sleep-deprived states caffeine's benefit is less reliable — sleep is still the better lever.
• 3Warm up with one or two practice taps — The first trial of any session is typically 20–40 ms slower than subsequent ones as your attentional system calibrates to the task. Use the first session of a day as a warm-up rather than your headline number.
• 4Train reactive sports and agility drills — Sustained training in sports that demand rapid responses — racket sports, martial arts, team ball sports — has been associated with faster simple and choice reaction times. The effect is partly neural (faster motor-unit recruitment) and partly attentional (improved stimulus anticipation).
• 5Minimise device lag for valid comparisons — Touchscreens, wireless mice, and LCD monitors all introduce hardware latency of roughly 10–50 ms. For personal trend-tracking this is fine provided you use the same device each session. Avoid comparing results across different hardware.