Free reaction time test — instant play, no signup, no download
Simple Click is reaction time stripped to its minimum — one signal, one response, no choice involved. It measures the shortest path from stimulus to movement, which is why it is the standard against which more complex reaction tasks are compared.
Wait for the signal.
Click the moment it appears.
Early clicks are rejected as false starts.
Multiple trials are averaged.
Your result is the average in milliseconds.
Easy gives 20 seconds and a large target; normal 15 seconds; hard 12; insane 10 with a target that starts small and shrinks fastest. Every hit moves the target to a random spot and makes it slightly smaller, down to a minimum size.
Each hit scores 1 point plus 1 extra for every five hits in your current combo. Clicking the empty area is a miss: it resets the combo but costs no points. Accuracy is hits divided by hits plus misses.
Simple reaction time. It sets the floor for every other timed task — no choice task can ever be faster than this.
Hitting a target quickly is governed by Fitts's law, first described by Paul Fitts in 1954: the time to reach a target grows with the distance to it and shrinks with its size, in a precise logarithmic relationship.
Fitts's law became one of the most-used models in human-computer interaction for designing buttons and menus. This game makes it visible — the target shrinks with each hit, so every point costs a little more precision than the last.
Hover; do not rest your finger on the button.
Do not anticipate. The random delay makes prediction a losing strategy.
Look at the signal's location rather than scanning.
Average five or more clean trials.
Because there is no decision step. Adding options adds time, roughly logarithmically — the relationship described by Hick's law.
Yes, by tens of milliseconds. Display refresh, input lag and browser timing all contribute. Compare only against your own runs on the same device.
Only modestly. Alertness, sleep and caffeine move it more than practice does.
Any click before the signal. They are rejected rather than counted, because otherwise guessing would beat reacting.