How to Solve Zip (One-Line Path Puzzle): Rules and Strategy

Zip is a path puzzle: one unbroken line, starting at 1, passing through every cell of the grid exactly once and touching the numbers in order. It feels like drawing — and it rewards looking a few steps ahead.

The rules

• Start on 1 and draw a single continuous path.
• Visit the numbered cells in order: 1, 2, 3 … up to the highest number, where the path ends.
• Pass through every cell exactly once.
• Move only up, down, left or right. Thick lines are walls and cannot be crossed.

Press on 1 and drag to draw. Drag back to undo the last steps, or tap a cell on the path to cut the line there.

Technique 1: Corners have only one way through

A corner cell has just two neighbours. Unless the path starts or ends there, it must enter from one and leave by the other. The same is true for any cell squeezed between walls or already-used cells.

Mark these forced corners early — they often fix whole edges of the board.

Technique 2: Never leave a pocket behind

Every empty cell must still be reachable. If your line cuts off a group of empty cells that can only be entered and not left, the path is already wrong.

Technique 3: Count the steps to the next number

Between number k and number k+1 the path must cover some cells. Look at which empty cells can only be reached during that stretch. If a region of the board would otherwise be skipped, the path has to detour through it before arriving at the next number.

Technique 4: Work from both ends

The last number is where the path ends, so its neighbourhood is just as constrained as the start. If you are stuck going forwards, think about how the line must arrive at the final number, and fill that part first.

Tips

• Walls matter: a cell with three walls around it is an endpoint or a dead end.
• Long straight runs along the edges are common and safe.
• Use undo freely — drawing is fast, so it is cheap to explore.

FAQ