Trail Making Test Online: Part A and Part B
The trail making test is one of the most widely used measures of processing speed and attention switching. Part A is a straight sequence — 1, 2, 3 — and measures how fast you can find and move. Part B alternates numbers and letters — 1, A, 2, B — and that alternation is the whole point: it forces you to hold two sequences at once and jump between them. The gap between your Part A and Part B times is where task-switching shows up.
Not a diagnostic tool. The trail making test has a long clinical history — standardised versions are used in dementia, MCI, brain-injury and stroke screening, with age-matched norms and trained administration. This online version has none of that. It is a practice and self-tracking exercise, not a diagnostic instrument.
A quiet round of Trail Making Test — Part A. When you start, everything else fades — just you and the task.
No sign-up needed. Press Esc to exit anytime.
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How to play
- Circles are scattered across the field, each labelled with a number or a letter.
- Part A: tap them in numerical order — 1, 2, 3, and so on.
- Part B: alternate between the two sequences — 1, A, 2, B, 3, C…
- Wrong taps count against your accuracy. Finish the trail to see your time and score.
Frequently asked questions
What is the trail making test?+
A timed connect-the-sequence task. Part A measures visual search and processing speed; Part B adds an alternation rule that requires switching between two sequences, which brings executive function and attention switching into play.
What's the difference between Part A and Part B?+
Part A is numbers only. Part B alternates numbers and letters, so you have to keep two counters running and swap between them on every step. Part B is reliably slower for everyone — the interesting number is how much slower you personally get, since that difference isolates the switching cost from raw speed.
Is the trail making test the same as a task switching test?+
Part B is one of the classic ways task switching gets operationalised, so the two overlap heavily. A dedicated task-switching test usually alternates abstract rules (odd/even, then high/low); TMT Part B alternates two familiar sequences instead, which makes it far easier to explain and just as demanding to do.
Is this a medical or diagnostic test?+
No. The trail making test has a long clinical history — standardised versions are used in screening for dementia, mild cognitive impairment, traumatic brain injury, and stroke, always with age-matched norms and trained administration. This online version has none of that. It is a practice and self-tracking exercise, not validated, not normed, and it cannot screen for or diagnose any condition. If you have concerns about your cognition, talk to a professional.
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