Sudoku Solver
Type in the puzzle from your newspaper or book. The solver checks that it was copied right, then shows the next number with the reason, one step at a time, so you can keep solving on your own.
How the steps work
- Only one number fits: the row, column and box of a square already have the other eight numbers.
- Only one place: in a row, column or box, a number can only go in one square.
- Harder puzzles reach a point where neither is enough. Then the solver points to the square with the fewest choices and says what goes there. In your own solving, that is where pencil notes help.
- A good puzzle has exactly one solution. If the check finds none or more than one, a number was probably copied wrong or left out.
Want a fresh puzzle? Play Sudoku online in three levels, or the Daily Puzzle.