Online attention trainer

Reaction test: green means go, red means stop

Also known as: Stop Signal, reaction test, Go/No-Go, reaction trainer

A signal lights up in the circle: tap as fast as you can on green, and don’t tap at all on red. A round of 40 signals takes about a minute. You can play 10 minutes a day without signing up.

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  • About a minute40 signals
  • Reactionin milliseconds
  • No sign-up10 minutes a day
  • Progress30-day chart
What it trains

Why take a reaction test

The exercise works on two skills at once: responding quickly to the right signal and holding back on the wrong one. There are more green signals, so your hand gets used to tapping, and you have to catch the red ones with your attention.

The round summary shows how many of the 40 answers were correct, how many times you tapped on red, how many greens you missed and your average reaction time. Once you sign up, your rounds are saved and your account shows a 30-day chart.

  • You hit Send before reading it againYour hand gets ahead of the check
  • You answer on autopilotA habitual action fires on its own
  • You react slowly when you’re tiredYou want to know your speed
  • You need a one-minute warm-upA simple rule, a fast pace

Reaction speed

Fast taps on green earn more points.

Self-control

You have to let the red signal pass, even though your hand is ready to tap.

Sustained attention

The signals come one after another, and the pace picks up toward the end.

Accuracy

A missed green earns nothing, and a tap on red costs two points.

Rules

How to play

  1. Start

    Press the start button and watch the circle in the center.

  2. Green: tap

    A green circle appears: tap it or press the space bar as fast as you can.

  3. Red: stop

    Let the red circle pass and don’t press anything.

  4. The pace picks up

    The time to respond gets a little shorter with every signal: from 1.1 seconds at the start to 0.65 at the end.

  5. Results

    After 40 signals we show your score, mistakes and average reaction time.

Play online

Reaction test online

Green means tap, red means don’t. You can play with the space bar. Without an account you get 10 minutes of play a day.

Stop Signal

Green circle: tap as fast as you can. Red: don’t tap. Trains reaction and self-control.

Free play left today without signing up: 10 min

Method

What the exercise is based on

The exercise is built like a Go/No-Go task: you respond to one signal and hold back on the other. Psychologists have long used tasks like this to study inhibition, the ability to stop yourself from doing a habitual action at the right moment.

The Stroop Test works on a close skill: there you put the brakes not on your hand, but on reading the word.

40signals per round20 in the Mix
70%of signals are greenthe rest are red, and you let them pass
1.1 sto respond at the startby the end of the round it shrinks to 0.65 s
Who it’s for

Which ages

Adults

A one-minute warm-up and a way to find out your average reaction time in milliseconds.

Kids

Part of the “Kids” collection: two colors and one rule. Suitable from age 6. Kids set

60+

Not part of the “60+” collection: the pace is fast, and the time to respond shrinks toward the end of the round. You can still give it a try; just compare with your own previous result.

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Questions

Frequently asked questions

How is the score calculated?

Green tapped faster than 0.4 seconds earns 2 points, slower earns 1. Holding back on red earns 1 point. Tapping on red costs 2 points. A missed green earns nothing. Taps that come too early, faster than 0.12 seconds, earn 1 point.

What counts as a good reaction time?

Compare yourself with yourself: the time depends on your device, mouse or finger, and how tired you are. Your account shows how your average reaction time changes.

Can I play with the keyboard?

Yes, instead of tapping the circle you can press the space bar.

Do I need to sign up?

No, you can play 10 minutes a day right away. Free sign-up lets you keep playing, save your results, track your progress and unlock the daily workout.

Does it work on my phone?

Yes, the trainer runs in the browser on phones, tablets and computers. There’s nothing to install.

Save your results and track your progress

Free sign-up: round history, a chart by skill and a daily workout of 5 exercises. No credit card needed.

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