Attention · Test

Go / No-Go

Respond to circles. Hold back on squares. Fast, but not too fast.

No account. No tracking. Your results stay with you.

Ready

Circle: go. Square: hold.

Respond to circles. Do nothing when a crossed square appears. Six practice trials, then 40 scored.

Needs to tell a circle from a square with a cross. Respond with Space, a click or a tap.

How this is measured

Shapes appear one at a time for half a second. Respond (Space, click or tap) to every circle. Do nothing when a square with a cross appears. Shape — not colour — is the cue.

Six practice trials first, then 40 scored: 30 circles and 10 squares in random order. You may answer up to 0.9 s after a shape appears. The pause between shapes is random (0.7–1.3 s).

Scoring

score = (hits + correct holds) ÷ trials × 100 reaction time = median of hits

A missed circle is an omission error; responding to a square is a commission error. Responding faster than 100 ms after a circle is counted as too early (a guess), not a hit.

Accuracy is the score because responding to everything as fast as possible would otherwise look like a great result.

What can affect the result

Your display: a 60 Hz screen shows a new frame every 16.7 ms, so a signal can appear up to one frame later than it was drawn; 120 Hz screens shorten that wait.
Your input device: mice, keyboards and touchscreens add their own delay (often 5–30 ms, sometimes more on wireless or Bluetooth devices).
Your browser and computer: background work, power-saving modes and battery saver can delay both drawing and input.
You: alertness, practice, time of day and whether you were ready for the trial.

What this does not mean

Go/No-Go is a classic interactive challenge. It is not a test of impulse control, attention disorders or anything else.
It is not a medical, psychological, neurological or hiring assessment, and it cannot diagnose or screen for anything.

Your results stay here

The test runs entirely in this browser tab. Results are saved only in this browser's local storage so you can compare with yourself — never uploaded, never tracked. You can clear them any time.

Go / No-Go

Go / No-Go test

How this is measured

Scoring

What can affect the result

What this does not mean

Your results stay here

Related tests

How this is measured

Scoring

What can affect the result

What this does not mean

Your results stay here