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dayu2333-jinyul

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What a Reaction Time Test Actually Measures (and Why Most Scores Are Off)

Most people take an online reaction time test, see 280ms, and think "is that good?" The answer: it depends heavily on the test setup.

Hardware matters more than your brain

  • Monitor refresh rate: 60Hz adds 8-16ms of input lag vs 144Hz
  • Mouse latency: wireless adds 5-15ms
  • Browser overhead: a tab with 20 extensions is slower than a clean profile

A 200ms score on bad hardware might be equivalent to 170ms on good hardware.

What's "normal"

  • Average human visual reaction time: 200-250ms
  • Audio reaction time: 150-170ms (sound processes faster)
  • F1 drivers: 100-150ms (trained, not innate)
  • Below 150ms on visual: likely anticipation, not raw reaction

The test design problem

Most reaction time tests use a single color change (red→green). This measures simple reaction time — one stimulus, one response. Real-world reaction time is choice reaction time (multiple stimuli, multiple possible responses), which adds 50-100ms.

A properly designed test: checkreaction.com — measures simple, choice, and sequence reaction times with hardware latency compensation.

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