Clicks Per Minute Click Chronometer Run the test

Reaction

Reaction Time Test

Five lights come on, then go out together. The clock starts the instant they do. Move early and it says so — a jump start is the point of the format, not something to hide.

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Click or press space to arm the lights

Average
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Best
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Attempts
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How to

How to run the reaction test

  1. Click the panel to arm it. The five lights come on one a second, as the real starting procedure does.
  2. Wait for all five to go out. The hold is randomised between 0.2 and 3 seconds, so the moment cannot be learned.
  3. Click the instant they go out. Space and Enter work too, and the clock reads to the millisecond.
  4. Repeat five or six times. The average across attempts is your reaction time; a single attempt is mostly luck.

The measurement

What a reaction time means

Why 200 ms is the honest benchmark

A visual signal has to reach the retina, travel the optic nerve, be recognised, become a motor command, and then move a finger through a switch. That chain costs about 200 ms for most adults, and roughly 150 ms is the floor for a trained human on a visual cue.

Anything under 100 ms is not a reaction. It means the press was already in motion before the lights changed — which is exactly why this tool flags a jump start rather than rewarding it. Racing drivers, who do this for a living, average around 200 ms and are considered exceptional below 150.

Reaction time is not click speed

They measure different things and train differently. Click speed is a sustained motor rate — how fast a finger can cycle a switch. Reaction time is a single latency, most of which is neural and largely fixed.

That is why the chronometer on this site deliberately excludes reaction time: its clock starts on your first click, not when the page loads, so a slow start never lowers a click rate. The two figures are worth knowing separately, and improving one does very little for the other.

The bench

Every tool on the bench

One instrument per input, all on the same clock. A rate is only comparable against the same tool and the same interval.

Background

Read the method

Longer entries on what this tool measures and where the number comes from.

Click speed and your hands

Rapid clicking is a physical activity with a real injury profile. The fatigue threshold arrives inside twenty seconds — information, not an obstacle.

Read the entry

Questions

Asked of the chronometer

Why do my attempts vary so much?

Because a single reaction is mostly noise. Spread across five or six attempts you will usually see a range of 40 to 60 milliseconds from the same person in the same sitting. The average is the figure worth keeping; the fastest single attempt is not.

Does my monitor affect the score?

Yes, and it is the largest non-human factor here. A 60 Hz panel can hold a frame for up to 16 milliseconds before you see it, plus the panel's own response time. None of that is your nervous system, and none of it can be separated out in a browser.

Is clicking faster than pressing a key?

Marginally, and not reliably. Both paths cost a few milliseconds through the device and the browser, which is inside the variation between your own attempts. Use whichever is comfortable — the panel takes a click, space or enter.