How to Use

• 1
  Click any cell and type a number 1–9 to enter your puzzle
• 2
  Leave unsolved cells empty — the solver fills them in
• 3
  Click Solve to instantly get the complete solution
• 4
  Or click New Puzzle to get a fresh puzzle to solve yourself
• 5
  Numbers shown in cyan are your original clues — green are solved cells

Sudoku Tips

Naked Singles — If a cell has only one possible number, fill it in immediately.

Scanning rows and columns — Look for a digit that can only go in one place in a row, column or box.

Box elimination — If a digit appears in two cells of a 3×3 box, eliminate it from the rest of that row/column.

Start easy — Always solve easy cells first. They unlock harder ones.

About This Solver

Our Sudoku solver uses a backtracking algorithm — the same method used by most professional solvers. It tries numbers systematically and backtracks when it hits a contradiction.

Works on any valid Sudoku puzzle including near-impossible expert puzzles. Solves in milliseconds.