Pro Tip

Before using pencil marks, see how far you can get on a hard puzzle with pure mental tracking.

Pro Tip
✓ Completed! 👍
4
2
6
5
9
4
8
7
5
2
6
1
8
4
8
3
8
3
2
7
5
9
2
6
8
Did You Know?

In 2007, a British newspaper published a Sudoku with no unique solution — they had to issue an apology.

Did You Know?