Single-player puzzles
Fill the grid with digits 1–9 so each row, column and 3×3 box contains each digit exactly once. Select a cell, then a number; use Erase or Backspace to clear it.
Sudoku is a solo 9×9 puzzle with three difficulties. Starting numbers are fixed; fill the empty cells using row, column and 3×3 box constraints. Checking helps you review progress, but a conflict-free board with empty cells is not a completed solution. Use the puzzle controls to start a new puzzle.
A row is missing only 2 and 7. Check the columns and boxes of its two empty cells. If one column already contains 7, that cell must be 2. This is elimination, not a guess. If neither cell is certain yet, inspect another row or box instead of entering a number at random.