Reaction time test
Wait for the box to turn green, then tap it as fast as you can. Five tries, then your average.
Five tries, no sign-up
When the box turns green, tap it or press Space as fast as you can.
What a reaction time test measures
This is simple reaction time: one signal, one response, no choice to make. It is the time it takes to see the change and act on it.
Your number also carries delay from your screen, your touchscreen or mouse, and the browser, and that delay differs from one device to the next. Compare your times with your own earlier tries on the same device, not with someone else's.
Where the test comes from
In 1868 F. C. Donders timed people responding to a signal, then timed them again when some signals had to be ignored. That second version is the Go/No-Go test, which measures holding back as well as speed.
In the app, the Go/No-Go test times your reactions as one of six short exercises, and the app keeps your history.
