🔢 This free printable sudoku prints on a single page. The answer key sits in a small strip at the bottom — fold it backward along the dotted line before you start, and you can solve honestly without ever seeing the solution. A real challenge — high-school level reasoning and vocabulary recommended.
| 5 | ||||||||
| 9 | 7 | 2 | 6 | |||||
| 2 | 3 | 8 | 9 | |||||
| 3 | 7 | |||||||
| 7 | 4 | 9 | 6 | 5 | 8 | |||
| 5 | 9 | |||||||
| 5 | 4 | 3 | 9 | |||||
| 4 | 9 | 1 | 7 | |||||
| 4 |
A Hard-rated grid usually has a handful of cells that resist simple scanning until you bring in a sharper technique. Here's where to focus:
These intermediate moves are usually enough to crack a Hard grid without guessing. For pairs, triples, and more advanced patterns, see our complete Sudoku strategy guide.
Hard Sudoku #4 starts with just 28 numbers, and the centre box is completely empty, with not a single given. The top and bottom rows each start with only one number. Singles take you about halfway, then you'll need a pointing pair followed by a naked or hidden pair before the rest falls into place.
With the centre box completely empty, start up top instead: row 2, column 4 (top-middle box). Row 2 rules out 2, 6, 7 and 9, column 4 rules out 1, 3 and 4, and the box itself already has an 8. The only digit left is 5.