Free Sudoku Solver
A Sudoku solver fills a valid 9x9 puzzle by checking every row, column, and 3x3 box for the numbers 1 through 9. Enter the givens from your puzzle, check for conflicts, and solve the board with candidate notes and step hints.
Built for puzzle nights and cafe tables
Use it to rescue a stuck puzzle, verify a hand-copied grid, or teach newer players how row, column, and box constraints narrow each move.
Find board games with GameShelfEnter your Sudoku grid
Use digits 1-9. Blank cells are treated as unknown squares.
Sample puzzle loaded.
Frequently asked questions
What is a Sudoku solver?
A Sudoku solver is a puzzle tool that fills a valid 9x9 Sudoku grid so every row, column, and 3x3 box contains the numbers 1 through 9.
How do I enter a Sudoku puzzle?
Type the known numbers into the grid and leave unknown squares blank. The solver treats blanks as cells it can fill.
Can this solver show solving steps?
Yes. After solving, it shows a compact trace of placements so you can review how the board was completed.
What does a conflict mean?
A conflict means the same number appears more than once in a row, column, or 3x3 box. Fix conflicts before asking the solver for an answer.
Does this work offline in my browser?
The puzzle is solved locally in your browser. Your entered Sudoku grid is not sent to a separate solving service.