Sudoku Solver
Enter your puzzle and let our solver find the solution
Enter the numbers from your Sudoku puzzle in the grid below. Leave empty cells blank.
Examples
Try these example puzzles:
Solver Options
How it Works
Our solver uses a backtracking algorithm to find the solution to any valid Sudoku puzzle:
- Find an empty cell in the grid
- Try placing digits 1-9 in this cell
- Check if the digit is valid in the current position
- If valid, recursively attempt to fill the rest of the grid
- If the recursive call fails, backtrack and try another digit
The algorithm will find a solution if one exists, or report that no solution is possible for the given input.
When using "Show Steps", you can visualize how the algorithm works:
- Yellow highlights cells where the algorithm is trying a digit
- Green highlights cells where a digit was successfully placed
- Red highlights cells where the algorithm needs to backtrack