Numberlink Solver
Build · Trace · SolveConnect matching letter pairs with non-crossing paths. Generate a random, solvable Numberlink (Flow) puzzle, drag your finger or mouse from a letter to draw its line, create your own puzzles, or solve automatically.
Numberlink rules explained with pictures
Connect each pair of matching letters with one continuous line. These mini-grids show how the connections work. They are examples, not additional puzzles to solve.
1. Connect matching letters
Draw one continuous path from an A to the other A, a B to the other B, and so on. Move up, down, left, or right into neighboring squares. Turns are allowed.
✓ Correct: one continuous blue path joins both A endpoints.
2. No diagonal shortcuts
Two matching letters can be diagonally next to each other, but you cannot draw a diagonal line between them. Move through squares sharing a side instead.
✗ Wrong: the dashed diagonal skips across corners.
3. Paths cannot cross or share a square
Each open square can belong to only one path. A path cannot cut through another path or another pair’s letter. Different paths may run alongside each other, but never overlap.
✗ Wrong: A and B both try to use the center square.
4. Usually every white square must be used
With “Require all white squares to be filled” checked, every white square must belong to exactly one path. Uncheck it if you are solving a variant that permits unused squares.
✓ Correct: both pairs are linked, with every square covered.
How to draw: Press Random game, use Draw paths mode, then drag from a letter to its match. You can also tap neighboring squares one at a time. Drag backwards to remove the last part of a path, use Undo to reverse a move, or Clear paths to start over. Press Check paths to see whether the puzzle is solved. Walls (dark squares) appear only if you add or import them; paths cannot pass through walls.