How do I play Sudoku?

Fill the 9×9 grid so each row, column, and 3×3 box contains digits 1–9 exactly once.

Does this Sudoku have a solver?

Yes. Use Solve → One Step for a hint or Solve → All to finish the puzzle automatically.

Yes, the game is free, runs in your browser, and works on desktop and mobile.

Show candidates

Very hard Time: 00:00 Filled: 0/81

Fill the grid so each row, column, and 3×3 box contains digits 1–9 exactly once.
Use Show candidates to display pencil marks for possible numbers.
Conflicts are highlighted in red; matching numbers are tinted for quick scanning.
Need a nudge? Try Solve → One Step or finish with Solve → All.