Reaction Time Test
The classic visual reaction benchmark. The panel turns red while you wait, then flips to green after a random one-to-four-second delay; click or press the spacebar the moment it changes. Click too soon and the try is thrown out — anticipating the light is exactly what the random delay is there to catch. A run is five valid tries: you get the average, your fastest single try, and a small chart of all five so you can see how consistent you were. The median human sits around 250 ms for a visual stimulus; gamers and athletes trend toward 200 ms, and nobody genuinely clicks below about 100 ms — that is anticipation, not reaction. Your best average is remembered on this device so you can try to beat yourself later.
Runs 100% in your browser — your puzzles never leave your device.
Read the full guide to this tool
Notes
- Visual reaction time is roughly 250 ms for the median adult; auditory reactions are typically 20-40 ms faster because the auditory pathway is shorter.
- Your monitor and input add real latency — a 60 Hz screen plus a typical mouse can add 20-40 ms that has nothing to do with your nervous system. Compare against yourself on the same setup, not against numbers from other hardware.
- Averages beat single tries: one lucky click means little, which is why the score is the mean of five valid attempts with early clicks rejected.
- Runs 100% in your browser — your words and puzzles never leave your device.
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