How to play Number Snake

Fill in the missing numbers so 1, 2, 3 … N form one chain of touching cells. Also known as Number path, consecutive-number chain.

The rules

Every cell gets a number from 1 to N (N = the number of cells), each used once.
Each number must touch the next one — side to side or corner to corner in Number Snake.
In the Orthogonal variant, consecutive numbers must touch side to side only.
Some numbers are given; fill in the rest so the chain is complete.

Choose a grid size and a difficulty, then press Generate Puzzle.
Choose Number Snake (diagonals count) or Orthogonal (sides only).
Click a cell and type a digit, or use the on-screen keypad. Notes switches to pencil marks.
Undo steps back; Force places one digit that has only one possible value; Check marks mistakes in red without giving away the answer.
Stuck? Send to Solver opens the same puzzle in the step-by-step solver. Send to Slate opens it as a board on the Slate whiteboard, to solve in front of a class.

① Build: choose the variant and grid size, then type the given numbers.
② Check Puzzle verifies it.
③ Solve It explains each placement — which gap it bridges and why only one cell fits.

Given 6 and 8 two cells apart diagonally, 7 must be in a cell touching both — often only one such cell is free.

Given 20 in a corner and 21 missing, 21 must be one of the three cells touching that corner; if two of those are already used, the third is 21.

Bridge the gaps. If 12 and 14 are given, 13 must be in a cell touching both.
Count the distance. Between given numbers 5 and 9 there are three missing numbers — the path between them must be exactly four steps.
Dead ends. A cell with only one free neighbour must be an end of the chain locally — the number before or after it goes there.
Work from both ends. 1 and N are usually given or easy to find; extend outwards from them.

Using diagonal moves in the Orthogonal variant.
Filling a path that works locally but leaves an isolated cell that can't be reached later.

Consecutive-number path puzzles of this kind became popular in the late 2000s; this site calls its versions Number Snake and Orthogonal.

Do diagonals count?

In Number Snake, yes. In the Orthogonal variant, no — only side-to-side moves.

What sizes are there?

The game makes 5×5 to 10×10 puzzles, Easy to Devilish.

Can I get a step-by-step solution?

Yes — press Send to Solver in the game, or enter a puzzle in the Number Snake Solver.