LinkedIn Zip Solver — Path Puzzle Solutions

What Is LinkedIn Zip?

Zip is LinkedIn’s daily path puzzle. The board is a grid with numbered dots and, on harder days, walls between cells. Your job: draw one continuous line that starts on dot 1, visits the numbered dots in ascending order, ends on the highest number, and passes through every cell exactly once— moving only up, down, left, and right, never through a wall. In math terms it’s a Hamiltonian path with waypoint ordering, which is what makes small boards surprisingly tricky.

How to Use the Zip Solver

1. Pick your grid size — 5×5 through 8×8.
2. Place the dots — click cells in number order; the counter increments automatically. Click a dot to remove it (later dots renumber), or use Erase mode to only remove.
3. Add walls — flip on Wall mode and click the dashed markers between cells.
4. Solve — the full path animates across the board with step numbers in every cell.

How the Solver Works

Finding a path through every cell exactly once is a Hamiltonian path search — brute force alone would be hopeless even at 7×7. The solver runs a depth-first search with two aggressive prunings. First, a connectivity check: after every step it flood fills the unvisited cells, and if any cell is cut off from the path head, the branch is abandoned — this is the “stranded pocket” a human notices when a corner gets sealed off. Second, dead-end detection: any unvisited cell (other than the final dot) left with only one open side could be entered but never exited, so the branch dies immediately. Dot ordering is enforced on the fly — the search refuses to step onto a dot out of sequence, and only steps onto the final dot when it is the last unvisited cell. Together these prune the tree so hard that 8×8 boards solve in well under a second in your browser.

Techniques to Solve Zip Yourself

• Corners are forced. A corner cell has two exits. If the path doesn’t start or end there, it must enter through one and leave through the other — often determining the whole first sweep.
• Walls make funnels. A row of walls with a single gap forces the path through that gap. Count how many times the path must cross between the two sides — each crossing uses one gap.
• Mind the parity. Color the grid like a checkerboard: each step alternates colors. On an even-cell board, dot 1 and the final dot must sit on opposite colors — if the endpoints have the wrong parity, no full-coverage path exists, and midgame the same logic tells you which cells can end a sweep.
• Sweep regions completely. Once the path leaves an area walled off by walls or by its own trail, it can never return. Fill each pocket fully before moving to the next number.
• Work backward from the last dot. The final number is the path’s endpoint — its neighborhood usually has only one viable approach direction.

Worked Example

Load the Example board (6×6, dots 1–6, three walls) and press Solve. Watch the path: dot 1 sits in the top-left corner, so the line has to sweep the top rows before dropping — the wall below R1C3 blocks the shortcut down, funneling the path along the full first row exactly as the corner rule predicts. Each numbered dot then acts as a checkpoint that fixes the direction of the next sweep, and the final dot in the bottom-left corner is reached only after every other cell is covered. Try moving one wall and re-solving to see how a single wall redirects the entire route.

Frequently Asked Questions