Sudoku
Solver-verified grids with one solution, every time
Sudoku is the world's most popular logic puzzle. Fill a 9x9 grid so that every row, every column, and every 3x3 box contains the numbers 1 to 9 exactly once. It sounds simple, but each puzzle demands careful reasoning. Our Sudoku is generated fresh every day with four difficulty levels, and every grid is verified to have exactly one solution.
How to Play Sudoku
- Each row must contain the numbers 1-9 exactly once.
- Each column must contain the numbers 1-9 exactly once.
- Each 3x3 box must contain the numbers 1-9 exactly once.
- Click or tap an empty cell, then pick a number or use your keyboard.
- Use pencil marks (small notes) to track candidate numbers.
- Complete the grid to win — mistakes are highlighted automatically.
Tips & Strategies
Start with the technique called "scanning": look at each row, column and box for numbers that can only go in one place. Use pencil marks for cells with 2-3 candidates, then use "cross-hatching" to eliminate options. A daily habit of just one Sudoku keeps your logic skills sharp.