4
1
7
8
4
9
6
7
5
8
4
2
2
8
1
9
2
6
3
7
5
4
9
3
Time 00:00
Mistakes 0
Ready
Hard Sudoku #12
Advanced patterns: X-Wings, triples and tighter candidate logic.
| Difficulty | Hard |
| Clues given | 24 of 81 |
| Technique score | 138.9 |
| Rated techniques | 5 |
Techniques this puzzle needs
Where to start
The first move on this board is a Naked Single: Row 4, column 4 already sees all eight other digits in its row, column and box, so it can only be 3.
Progress is saved in this browser automatically. Use the keyboard: arrows to move, 1–9 to fill, N for notes, H for a hint.