Reaction Time Test

Assess your reaction time, reflexes, and how quickly your brain processes and responds to stimuli.

Brain Speed & Reaction

Reaction Time Test

Reaction time measures how quickly you can respond to a stimulus. It's influenced by age, fitness, fatigue, and cognitive health. Faster reaction times are associated with better cognitive function and are important for driving, sports, and daily safety. This self-assessment evaluates your perceived reaction speed in everyday situations.

3 min10 questionsFree, no sign-up

This test is designed for entertainment and self-reflection purposes. Results are not clinically validated and should not be used as a substitute for professional assessment.

What you'll find out

  • Lightning Fast
  • Quick
  • Average
  • Could Improve

What reaction time tells you about your brain

Reaction time (RT) measures how quickly the brain and nervous system can detect a stimulus and produce a response. It reflects processing speed — one of the most consistent predictors of general cognitive ability and a reliable marker of neurological health.

Average simple reaction time in healthy adults is around 200-250ms. RT slows with age, fatigue, alcohol and medication, and neurological conditions. It improves with exercise and adequate sleep.

Reaction time is used clinically to assess the effects of sleep deprivation, concussion, medication, and neurodegenerative conditions. It's also used in sports science to assess athlete readiness and identify performance factors.

Frequently asked questions

What affects reaction time most?
Sleep deprivation has the largest effect — even moderate sleep restriction significantly slows RT. Caffeine has a modest positive effect. Alcohol and many medications slow RT substantially.
Does reaction time decline with age?
Yes, steadily from the 20s onwards. The decline is gradual but measurable. Regular exercise mitigates but doesn't eliminate age-related RT slowing.