Sudoku Solver

Get help to solve sudoku puzzles. Type in the numbers from your puzzle, then let the solver finish it, or reveal just one number when you are stuck.

How to use the sudoku solver

1. Click a square and type the numbers from your puzzle. Use the arrow keys to move around the grid.
2. Leave the squares you don't know empty.
3. Press Solve it to see the full solution, or Show one number to get a single hint and keep solving yourself.

Numbers that break the rules, for example two 5s in the same row, are shown in red so you can spot typing mistakes.

Solve it yourself first

A solver is handy when you are stuck or want to check your answer, but the fun of sudoku is cracking it yourself. Try the Show one number button before you reveal the whole solution. The solver always picks the square with the fewest possible numbers, which is usually the square you should look at next.

Want to get better? Read our guide to solving sudoku and our sudoku tips on the strategies that experienced players use.

How does the solver work?

The solver works like a very fast, very patient player. It finds the empty square with the fewest possible numbers and tries each of them in turn. If a choice leads to a dead end, it steps back and tries the next one. Because it always starts with the most constrained square, even the hardest puzzles are solved in a fraction of a second. It also checks whether your puzzle has exactly one solution, as a proper sudoku should.