Thread puzzle, fresh every time.
Trace one unbroken path through every square. Your running total must hit each target in order, then the next one starts from zero.
One answer, square by square:
Each puzzle is built from a random path, so every board has at least one answer. Nothing is stored or sent.
How to solve one
Start anywhere. Add the squares you pass until the total matches the first target, then mark that square and start again from zero for the next target. Keep sums small in your head: most boards have a 1 and a 9 that have to meet somewhere.
When you're stuck, work backwards from the last target. It has to finish on the last square, which narrows the route quickly.
Love the daily one? The app has many more
Sumthread is a calm number-path puzzle for a five-minute break:
- One continuous thread: drag across tiles or tap step by step, and backtrack anytime
- Exact-match cues show which neighbours complete the active target
- Finish any board with zero hints and zero undos to earn the Clean Weave seal
Get Sumthread on the App Store
Free to download for iPhone. Details from the app's App Store description, checked 11 November 2026. This maker is a separate web tool and its boards are not the app's.
Questions
What are the rules of a number-path puzzle?
Trace a single continuous path through every square, moving up, down, left or right with no diagonals and no square used twice. Your running total must hit each target in order; when it does, that square is a checkpoint and the next target starts from zero. The last target must finish on the last square.
Is every puzzle solvable?
Yes. The maker first draws a path through the grid, puts numbers on the squares, then works out the targets from that path. So there is always at least one answer, and Show answer reveals it.
Is anything saved?
No. Each puzzle is generated in your browser and nothing is stored or sent.