SART Test — Free Online Mind-Wandering & Sustained Attention

The Mind-wandering (SART) task asks you to tap a button every time a digit from 1 to 9 appears in the center of the screen, except when the digit is 3, where you hold back. There are 225 digits in total, with each digit appearing 25 times in shuffled order, so you only need to withhold on the 3 just 25 times. Because nearly every trial calls for a simple tap, your hand quickly slips into autopilot, and the real question is whether you catch the rare 3 in time.

Each digit is visible for only 0.25 seconds before it turns into a mask, a circle with a cross through it, and the next digit always arrives 1.15 seconds after the previous one appeared. The pace stays the same whether you respond quickly or slowly. Digit size keeps switching among five sizes, but only the digit itself matters. There is no practice block: the test starts right away, runs without pauses, and takes a little over 4 minutes.

The headline result is a focus retention score out of 100. It goes down with the share of the 25 no-go trials on which you tapped the 3 anyway: never pressing on 3 gives 100, and each slip costs 4 points. Two or fewer slips are read as attention held very well even through a dull task, 3–5 as good, and 6–10 as the typical range almost everyone shows. More than that suggests that responding became automatic and your attention may have drifted away from the task.

The detailed report shows the shape of your errors. It lists your mean response time on correct taps and how much it fluctuates (coefficient of variation: under 15% is very steady, 25% or more is uneven), omissions where you missed a digit you should have tapped, and anticipations faster than 100 ms that look like guesses. It also splits the test into five blocks of 45 trials to show whether you slowed down or sped up later on, and checks whether the four responses right before each slip were faster than usual, known as pre-error speeding.

The SART (Sustained Attention to Response Task) was introduced by Robertson and colleagues in 1997 to see whether the everyday attentional slips people experience also show up in a simple laboratory response task. It has since been used widely in research on mind-wandering, the moments when thoughts drift away from a dull task. Soundary's version is its own web implementation that follows the original's fixed pace and rare no-go structure. The result is a self-check of your attention on that day, not a diagnosis.

Scores shift easily with sleep, fatigue, caffeine, time of day, background noise and the device you use. If you retake it, leaving a few days to a few weeks in between and testing at a similar time on the same device makes the comparison with your previous result much fairer. The comparison-with-others graph is a provisional reference estimate made before enough real data has been collected, so read it lightly. For classes or studies, a group link lets participants join anonymously without signing in.