Drag from a number to draw its line, or tap a number and then the neighbouring cells. Drag over another line to cut it. Connect every pair and fill the whole grid.
Numberlink
Connect the matching numbers and fill every cell.
About Numberlink
Numberlink is a classic pencil-and-paper logic puzzle, made popular worldwide by mobile "connect the dots" games. The grid holds pairs of matching numbers; your job is to join each pair with a single line that moves horizontally or vertically, never crosses another line, and together with the other lines fills every cell of the board.
Ludingo generates 1000 puzzles per difficulty — 5×5, 7×7 and 9×9 — and checks that each one has exactly one solution. Every board has a stable id, so a shared link opens the very same puzzle for your friend, and today's board is part of the Daily Challenge.
How to play
- Start a line on any number and drag (or tap cell by cell) towards its matching number.
- Lines move up, down, left or right — never diagonally — and can never cross or overlap.
- Every cell of the grid must belong to a line; the puzzle is solved when all pairs are connected and nothing is empty.
- Drag back along a line to shorten it, start again from a number to redraw it, or drag across another line to cut it.
How to solve Numberlink — strategy
Start with the forced lines. Pairs that sit right next to a wall or a corner often have only one sensible route; draw those first and the rest of the board gets smaller.
Hug the edges. In a puzzle where every cell must be filled, lines usually run along the border instead of cutting through the middle. If a line could follow the edge, try that route first.
Never leave a single empty cell boxed in. Every empty cell needs two free neighbours so a line can pass through it — a cell with only one free side is a dead end, so the current route is wrong.
Watch for detours. A line that makes a U-turn next to itself is almost never correct: in a unique puzzle it could always be shortcut, so look for a straighter path.
Tips for faster solves
- Solve the corners first — a corner cell has only two neighbours.
- Long pairs far apart usually wrap around the outside of the grid.
- Drag over another line to cut it instead of resetting the board.
- Use the Filled counter: 100% plus all pairs connected means solved.
Questions about Numberlink
What are the rules of Numberlink?
Connect each pair of identical numbers with one continuous line. Lines run horizontally or vertically, may not cross or share a cell, and the finished board must have every cell covered by a line.
Does every puzzle have exactly one solution?
Yes. Each Ludingo puzzle is checked by a solver before it is used — there is exactly one way to connect the pairs so that every cell is filled without lines touching themselves in a detour.
How does difficulty work?
Easy boards are 5×5 with 4–6 pairs, medium boards are 7×7 with 6–8 pairs, and hard boards are 9×9 with 8–11 pairs. Bigger grids mean longer lines and more ways to go wrong.
Is Numberlink the same as Flow?
It is the same family of puzzle: Flow Free popularised the coloured version on phones. Numberlink is the original name of the puzzle type; on Ludingo each pair has both a colour and a number, so it is playable for colour-blind players too.
What do hints do?
A hint draws the complete correct line for one pair that is not yet right, cutting any of your lines that are in its way. Hints are counted in your result and have a 30-second cooldown.
Can I play on my phone?
Yes — drag with your finger to draw lines; the board never scrolls while you draw. On a keyboard, move with the arrow keys and press Enter on a number to start a line, then use the arrows to extend it.