Sudoku Solver
Type your 9x9 puzzle into the grid and let the solver finish it. It runs a real backtracking algorithm right in your browser, shows the solve time and step count, and checks your entries for mistakes.
Enter your puzzle
Only digits 1 to 9 are accepted. Leave unknown cells empty. Your original numbers stay dark and bold; the numbers found by the solver appear in blue.
How to use this solver
- Enter the puzzle. Type the given digits 1 to 9 into the matching cells and leave the rest empty.
- Check it first (optional). Press Validate to catch duplicate digits in any row, column or 3 by 3 box before solving.
- Press Solve. The backtracking solver fills the grid, highlights its own answers in blue, and reports the solve time and step count.
- Start over anytime. Press Clear to empty the grid, or Load Sample Puzzle to try a ready made puzzle.