How this attention test works
This is a sustained attention test modelled on the SART (Sustained Attention to Response Task). Digits from 1 to 9 appear in the middle of the box, one at a time. Each digit is shown for 250 milliseconds and is then covered by a ring with a cross for 900 milliseconds, so a new digit arrives every 1.15 seconds. It measures staying on task over minutes; resisting a single distracting cue is what the Stroop test measures.
Your rule is simple:
- Tap the box (or press Space or Enter) for every digit except 3.
- Hold back when the digit is a 3.
Press Start 3-minute test for the full version: 156 digits, just under 3 minutes. If you are short on time, Quick 1-minute version runs 52 digits. Digits come in shuffled groups of nine, so one in nine is a 3: about 17 in the full test and 5 or 6 in the quick one. The size of each digit changes at random, so you have to read it rather than react to its shape. You can leave at any time with Stop; an unfinished run is not scored.
The trick is that pressing quickly becomes a habit. After a few dozen "go" digits, your hand starts to move on its own, and the 3 slips through. That moment of autopilot is exactly what the test is designed to catch.
How your attention score is calculated
The result card shows a score from 0 to 100. The formula is:
Attention score = 100 × (1 − 0.6 × commission rate − 0.4 × omission rate)
- Commission rate = the 3s you pressed ÷ all 3s shown. This is the "Pressed on 3" stat.
- Omission rate = other digits you did not press ÷ all other digits. This is the "Missed digits" stat.
- The result is rounded and kept between 0 and 100.
Pressing on a 3 weighs more (0.6) than missing a digit (0.4), because pressing on a 3 is the clearest sign of attention drifting into autopilot. Missing several digits in a row usually means your mind wandered off completely.
Two more numbers are shown but are not part of the score:
- Average response: your mean reaction time on digits you pressed.
- Timing variability: the standard deviation of those reaction times divided by their mean, as a percentage. A steady rhythm gives a low number; a rhythm that speeds up and stalls gives a high one. Keeping time with no cue at all is a different skill, tested by the time perception test. Researchers often look at this kind of variability alongside errors, because inconsistent timing can signal fluctuating attention.
The bands on the card (90 or more, 75–89, 60–74, under 60) are labels for this test only. We do not compare you with a population average, because no published norm exists for this exact version and scoring. Your personal best and recent scores are kept in this browser, so you can compare yourself across days or times of day.
Where the task comes from
The SART was introduced by Ian Robertson and colleagues in 1997 in a paper titled "Oops!". In their version, 225 digits were shown over about 4.3 minutes, with the same 250 ms digit and 900 ms mask timing and five different font sizes. They found that people who made more errors on the task also reported more everyday attention slips on a questionnaire. They tested both people with traumatic brain injury and healthy volunteers.
Our version keeps the timing and the "press for everything except 3" rule, but shortens the run to 3 minutes or 1 minute and adds a single summary score so the result is easy to compare between rounds. Holding and updating information, rather than keeping a steady watch, is what the working memory test checks.
What affects your result
- Time of day and sleep. Sustained attention drops when you are tired. Try the test at different times and compare. The chronotype test suggests when your own best hours are likely to be.
- Speed vs. caution. Pressing faster raises the chance of hitting the 3. Some people slow down to protect accuracy. Both strategies are fine; the score rewards fewer slips, not speed.
- Distractions. Notifications, music with lyrics or a busy room all make a real difference in a three-minute task.
- Device. On a touchscreen, make sure your finger is resting near the box. Display delay affects your average response but not the error counts.
Limits of this test
The quick 1-minute version has only about 5 or 6 no-go digits, so a single slip changes the score a lot. Use the 3-minute version when you want a steadier number.
This is a self-check for curiosity and practice. It is not a test for ADHD or any other condition, and a low score on one run says little on its own. If attention problems affect your work, studies or relationships, talk to a qualified professional.
More tests of attention, memory and thinking are on the memory and brain tests page.
Source
- Robertson, I. H., Manly, T., Andrade, J., Baddeley, B. T., & Yiend, J. (1997). 'Oops!': Performance correlates of everyday attentional failures in traumatic brain injured and normal subjects. Neuropsychologia, 35(6), 747–758.
Frequently asked questions
How long is the attention span test?
The full version shows 156 digits, one every 1.15 seconds, which takes just under 3 minutes. The quick version shows 52 digits in about 1 minute.
Why do I have to press for every digit except 3?
Pressing most of the time builds a habit. Holding back on the rare 3 then needs active attention. When your focus drifts into autopilot, you press on the 3, and that slip is what the test measures.
How is the attention score calculated?
Score = 100 × (1 − 0.6 × commission rate − 0.4 × omission rate). The commission rate is the share of 3s you pressed; the omission rate is the share of other digits you did not press. The result is rounded and kept between 0 and 100.
What is timing variability?
It is how much your reaction times vary, shown as the standard deviation divided by the mean. A low percentage means a steady rhythm. It is shown for information and is not part of the score.
Is the 1-minute version accurate?
It is fine for a quick check, but it has only about 5 or 6 digits where you must hold back, so a single slip moves the score a lot. The 3-minute version gives a steadier result.
What is a normal attention score?
There is no published norm for this exact version and formula, so we do not show one. Compare your own scores across days and times of day instead.
Can this test tell if I have ADHD?
No. It is a short self-check for curiosity and practice, not a diagnostic test. If attention problems affect your daily life, talk to a qualified professional.