Sudoku guide
Hard Sudoku online
Hard Sudoku is for players who already know the rules and want a slower, more tactical solve.
Play hard Sudoku
No install, no timer pressure
5
3
6
1
5
9
8
6
8
3
7
6
6
2
8
4
9
5
7
9
What to expect
Hard puzzles have fewer immediate placements. Progress often comes from narrowing pairs, tracking candidates, and revisiting blocked cells.
Recommended approach
Use notes, avoid guessing, and look for rows or boxes where a number can only appear in one location.
Practice