ReactScore
Reaction + inhibition

Go / No-Go Test

Green means go: react. Red means stop: do nothing. Sounds easy until the green ones lull you into a rhythm and a red one slips through. This is the go/no-go test, and it measures not just your speed but your brakes: how well you can stop a reaction you’ve already started.

Go / No-Go

Tap on green. Do nothing on red. Press to start.

Speed is only half the test

A normal reaction test rewards one thing: going fast. But going fast is easy when going is all you ever do. The moment some signals mean don't, the task gets honest. Your brain builds a habit out of the green ones (react, react, react), and that momentum is exactly what trips you up when a red one appears. Stopping a reaction you've already begun is a different, harder skill, and it lives in a different part of the brain than the reacting does.

Those mistaken taps on red (commission errors) are the number psychologists actually care about. They are a clean, simple window into impulse control, which is why versions of this test show up in research on attention and self-regulation. Here, treat them as a score to beat: can you stay fast on green without getting sloppy on red?

How to do well

  • Don't pre-load. If your finger is already twitching before the signal, red will catch you.
  • Stay even. The temptation is to speed up after a run of greens. That's exactly when a red sneaks through.
  • Accept a little slower. A touch more caution on green for far fewer red mistakes is usually the better trade.

Frequently asked questions

What does the go/no-go test measure?
Two things. Your go reaction time (how fast you respond to the GO signal) and your response inhibition, how often you wrongly react to a NO-GO signal. Those mistaken reactions, called commission errors, are the real point: they show how well you can stop an action mid-impulse.
Why do I keep clicking on the red ones?
Because most signals are GO, your brain settles into a "react" habit, and stopping that habit takes active effort. When a NO-GO appears, the urge to respond is already in motion. Catching it is the skill the test trains, and tiredness and distraction make it noticeably harder.
How is this different from a normal reaction test?
The standard reaction test only measures going: you always react. Go/no-go adds the harder half: not reacting when you shouldn't. It is closer to real situations like driving, where stopping a planned move matters as much as making one.

More reaction tools

Reaction Time TestThe classic visual test, median of 5.F1 Reaction TestLaunch off the five red lights.Audio Reaction TestReact to a tone, not a color.Aim TrainerClick targets fast and accurately.Ruler Drop TestThe classic physics method, simulated.Reaction Time GameStreaks, levels and a running score.Color Reaction TestReact only to the right color.Choice Reaction TestHick's law in action.2-Player Reaction TestSettle it head-to-head.Driving Reaction TestEmergency stop + stopping distance.Daily ChallengeOne shared test a day. Keep your streak.Reaction Age TestSee how old your reflexes really are.