EveryMemoryThe Trail Making Test, Explained
The trail making test asks you to connect scattered numbers — and then alternating numbers and letters — as fast as you can, testing task-switching and visual search.
Part of the guide: Understanding Memory Loss and Forgetfulness: A Calm, Reassuring Guide →
⚡ Quick answer
The trail making test has two parts: in Part A you connect numbered circles 1-25 in order as fast as you can; in Part B you alternate numbers and letters (1-A-2-B-3-C). Part A measures visual scanning and speed; Part B adds task-switching — flipping between two sequences. It's a timed self-check, not a diagnostic test.
Key takeaways
- Part A connects numbers 1-25; Part B alternates numbers and letters, both timed.
- Part A taps visual scanning and speed; Part B adds task-switching.
- The B-minus-A gap isolates the pure cost of switching between sequences.
- Strong practice effects and tiredness move the time; it's no standalone diagnostic.
The trail making test is a pen-and-paper classic that survives because it's so revealing. In Part A, you draw a line connecting scattered circles numbered 1 to 25 in order, as fast as you can. In Part B, the circles hold both numbers and letters, and you alternate between them: 1, A, 2, B, 3, C, and so on. The clock is running the whole time.
Part A mostly measures how fast you can scan and connect — visual search plus speed. Part B adds the twist that gives the test its bite: you have to switch back and forth between two sequences without losing your place. The gap between your Part A and Part B times is what makes it informative.
Part A vs. Part B
Part A is the warm-up: a single sequence (numbers in order) that taps visual search and motor speed. Part B layers on cognitive flexibility — you must hold two sequences in mind and alternate between them, suppressing the pull to keep counting straight up.
Because Part B adds task-switching on top of everything Part A demands, it's almost always slower. The B-minus-A difference is the interesting number: it isolates the extra cost of switching from the raw speed of scanning.
| Part | What you connect | Mainly measures |
|---|---|---|
| Part A | Numbers 1-25 in order | Visual scanning and speed |
| Part B | Alternating 1-A-2-B-3-C | Task-switching and flexibility |
| B minus A | The difference in time | Pure switching cost |
What it measures
The trail making test taps a stack of skills: visual search (finding the next target on a cluttered page), processing speed, motor control, and — in Part B — set-shifting, the executive ability to switch between rules or sequences. That switching component is why it's a staple in research on cognitive flexibility.
It overlaps in spirit with task-switching games where you flip between rules under time pressure. The shared core is the cost of changing your mind quickly — see how to improve focus and concentration for where that skill shows up day to day.
What a result does and doesn't mean
A slower Part B, or a big B-minus-A gap, can reflect anything that makes switching harder on the day: fatigue, distraction, low familiarity with the format, or simply a shaky hand on a touchscreen. Practice effects are strong too — your second attempt is almost always faster, which says more about familiarity than ability.
It is not a diagnosis. The trail making test is used inside clinical batteries by professionals, but on its own, as a casual self-check, it can't assess any condition. Treat your time as a self-relative snapshot, not a verdict. See types of memory tests.
Reading your own trail
If you try it, time both parts and note the difference, run it more than once, and compare your own results over time under similar conditions rather than to a stranger's score. The switching cost (B minus A) is the most stable thing to watch.
And remember the ceiling on what it tells you: getting faster at trail making mainly makes you faster at trail making. For a calmer, broader self-check, see how to test your memory.
✅ Try this today — Make your own trail test
A paper version you can time yourself.
- Scatter circles numbered 1-15 randomly on a page; draw a line connecting them in order, timed.
- Now make a second page mixing 1-8 and A-G; connect them alternating 1-A-2-B-3-C…
- Time both. The second sheet should take noticeably longer — that gap is the switching cost.
- Repeat next week under similar conditions and compare your own times, not anyone else's.
⚠ When to talk to a professional
The trail making test is a fun, non-medical self-check, not a diagnostic instrument. A slow time on a tired day means nothing clinical — professionals use it within full assessments, so don't self-diagnose from it.
