Hard Sudoku

About hard sudoku

Hard Sudoku asks you to look at the whole grid at once. Progress comes from spotting patterns — a number confined to one line of a box, or a pair of squares that must hold the same two candidates.

Pencil marks are essential here. Keep them tidy and let each placement prune the possibilities elsewhere. Every Hard puzzle still has a single solution reachable without guessing.

Tips

• Turn on Notes to pencil in candidates, then eliminate them as you place numbers.
• Scan one digit at a time across the whole grid to find where it fits.
• Use the Hint button to learn the next logical step, not just the answer.