Pro Tip

For hard puzzles, do a full pencil-mark pass before making any moves. Incomplete marks are worse than no marks.

Pro Tip
✓ Completed! 👍
4
2
1
2
5
7
1
9
6
9
5
3
8
8
2
7
4
8
1
7
9
3
2
Sudoku Trivia

The longest Sudoku solving session in a competitive setting lasted over 8 hours — an endurance format.

Sudoku Trivia