Hard Sudoku
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Play Free Sudoku Online!
Challenge your logic with our free Sudoku puzzles. Fill the 9×9 grid ensuring each row, column, and 3×3 box contains digits 1-9 without repetition. Perfect for all skill levels!
Why Play Sudoku?
Sudoku is more than just fun; it's a brain workout! Regular play sharpens problem-solving skills, boosts concentration, and improves memory. It's the ideal mental break.
How to Play
- The goal: Fill the 9×9 grid with digits 1-9.
- The rules: Each row, column, and 3×3 box must contain each digit exactly once.
- Use the pre-filled numbers and logic to deduce the rest.
- Incorrect moves (duplicates in a row, column, or box) count as mistakes.
Handy Sudoku Tips
Start Simple
Focus on rows, columns, or 3×3 sections that are already mostly filled. This limits the possibilities for empty cells.
Scan for Singles
Look for cells where only one number is possible based on the existing numbers in its row, column, and block.
Use Pencil Marks
Toggle Notes mode () to jot down potential candidates in empty cells. This helps visualize possibilities.