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Utility

Reaction Timer

Measure your reflex speed. Wait for the screen to turn green, then click or press Space/Enter as fast as you can. Tracks best, average, and session history.

Reaction Timer
Client-side onlyFast & private
Session

We recommend 5–10 for a quick test.

Random delay (ms)

GO cue appears after a random delay within this range.

Options & actions

Adds a short tone with the visual cue

Notes

Click or press Space/Enter only when the area turns green. Early clicks are flagged as Too soon and the trial restarts.

Test

5 trials • Beep off • 1200-3000ms delay
Best ever: —
Reaction area
Get ready…
Trial 1 / 5
Results
Best
— ms
Average
— ms
Median
— ms
  • Std Dev: — ms
  • Trials recorded: 0
  • Reaction time = time between the green cue and your click/press.
History (last 10)

No sessions yet.

How to Use the Reaction Timer

This free, client-side Reaction Timer measures the time between a random visual cue and your response. You can run multiple trials, optionally play a beep with the cue, and review best, average, and median times. Nothing is uploaded.

  1. Set trials & delay: Choose how many trials to run and the min/max random delay.
  2. Start: Click Start. The area turns yellow — wait until it turns green.
  3. React: As soon as it’s green, click/tap or press Space/Enter.
  4. Avoid false starts: Clicking early shows “Too soon!” and the trial restarts.
  5. Review results: Big tiles show your best, average, and median. A session history is saved locally.

Scoring

  • Reaction time: time from cue onset to your input (ms).
  • Average: arithmetic mean across valid trials.
  • Median: middle value (robust to outliers).
  • Std Dev: variability across trials.

Tips

  • Keep a consistent posture and finger placement; avoid hovering clicks.
  • Increase trial count for more stable averages (10–20 trials recommended).
  • You can focus the pad and react via keyboard if that’s more comfortable.