5
2
7
8
9
3
1
2
9
4
9
5
9
2
1
8
6
5
3
1
4
3
6
9
3
5
Time 00:00
Mistakes 0
Ready
Hard Sudoku #139
Advanced patterns: X-Wings, triples and tighter candidate logic.
| Difficulty | Hard |
| Clues given | 26 of 81 |
| Technique score | 125 |
| Rated techniques | 4 |
Techniques this puzzle needs
Where to start
The first move on this board is a Naked Single: Row 4, column 8 already sees all eight other digits in its row, column and box, so it can only be 7.
Progress is saved in this browser automatically. Use the keyboard: arrows to move, 1–9 to fill, N for notes, H for a hint.