What is Numberlink?
Numberlink is a logic puzzle where matching endpoints must be connected by continuous paths. Each pair has its own colour, paths may not cross or share cells, and the finished board fills the entire grid.
This free online Numberlink game includes multiple grid sizes and easy, medium and hard difficulty settings. The generator builds a complete path layout, keeps only the endpoints as clues, and favours lively routes that snake through different parts of the grid.
- Connect every matching pair of coloured endpoints.
- Move horizontally or vertically from one cell to the next.
- Paths cannot cross, branch or overlap.
- Every empty cell must be filled by exactly one path.
- Finished boards are accepted when every pair is connected and every cell belongs to one path.
How to play Numberlink online
Click or tap one endpoint, then click neighbouring cells to extend that colour. Continue until it reaches the matching endpoint. If you make a detour, click an earlier cell in the same path to trim the line back.
The Check button looks for structural problems without filling the board for you. Hint adds the next useful cell for the selected colour, while Solution reveals one full set of paths when you want to study an answer.
- Start with pairs that sit near an edge or corner.
- Fill forced corridors before opening the middle of the grid.
- Avoid trapping a single empty cell away from every endpoint.
- Do not block a pair from reaching its matching colour.
- Use the whole board: a finished Numberlink has no unused cells.
Numberlink grid sizes and difficulty
Small Numberlink boards are quick, friendly and good for learning the rhythm of the puzzle. Larger boards create longer routes, more colour pairs and more moments where one path controls several later paths.
Difficulty changes the mix of path lengths and the amount of open space. Easy puzzles have shorter, more guided connections. Medium puzzles ask for more planning. Hard Numberlink puzzles use longer routes where order and space management matter.
- 5x5 Numberlink is a warm-up size for fast solves.
- 7x7 Numberlink gives a balanced everyday puzzle.
- 9x9 Numberlink has longer paths and tighter space.
- Easy, medium and hard change path length, pair count and solving pressure.
- New puzzle creates another full-grid board for the selected settings.
Numberlink strategy tips
The best Numberlink strategy is to think about space before drawing too far. A path that looks obvious can still be wrong if it cuts the grid in two or blocks another pair from connecting.
Look for forced moves. Endpoints in corners have fewer exits, edge corridors can become mandatory, and nearly closed areas often reveal which colour must pass through them.
- Connect tight pairs and edge pairs first.
- Trace possible routes in your head before committing long paths.
- Keep the centre flexible until the outer paths are clear.
- Watch for one-cell pockets, because every cell must be used.
- When stuck, ask which pair has the fewest legal exits.
Why interesting Numberlink paths matter
A strict single-solution Numberlink board can be satisfying, but it can also push generated grids toward square frames and predictable corridors. For play, the board still needs clear rules, but the route shapes should feel lively.
The puzzles on this page prioritise full-grid path covers with a more interesting hero route. If a board has more than one valid finish, the game accepts any complete solution that connects every pair, avoids overlaps and fills every cell.