🔢 This free printable sudoku prints on a single page. The answer key sits in a small strip at the bottom — fold it backward along the dotted line before you start, and you can solve honestly without ever seeing the solution. A real challenge — high-school level reasoning and vocabulary recommended.
Fill the grid so every row, every column, and every 3×3 box contains the digits 1 through 9 exactly once. Fewer starting clues — sharper logic required.
8
9
5
7
1
6
3
5
2
3
8
6
9
1
2
9
7
5
1
5
8
9
5
1
4
1
2
5
7
1
7
9
✂ fold backward along this line to hide the solution ✂
Solution hidden on screen — it prints automatically.
Solution
4
8
6
2
1
9
7
5
3
7
9
1
6
3
5
8
2
4
3
5
2
4
8
7
6
1
9
5
3
8
9
6
1
4
7
2
9
2
4
8
7
3
1
6
5
1
6
7
5
2
4
9
3
8
8
7
9
3
5
6
2
4
1
6
4
3
1
9
2
5
8
7
2
1
5
7
4
8
3
9
6
How to Solve This Sudoku
Hard Sudoku puzzles like this one deliberately leave fewer givens, so basic scanning alone won't get you all the way — you'll need at least one or two intermediate techniques.
Look for naked pairs. When two cells in the same row, column, or box can only hold the same two candidate numbers between them, those two numbers can be eliminated from every other cell in that group.
Try pointing pairs. If a candidate number appears in only two or three cells of a box, and those cells share a row or column, you can eliminate that number from the rest of that row or column outside the box.
Save single-candidate guessing for last. Exhaust every logical elimination technique before considering a guess-and-check branch — a true Hard puzzle should still be solvable without one.
These are the core moves that separate Hard grids from Easy ones. Full walkthroughs of pairs, triples, and X-wing patterns live in our complete Sudoku strategy guide.
About This Puzzle
Hard Sudoku #3 trims the starting numbers down, which means a few cells will resist simple scanning until you bring in pairs or pointing-pair logic. A solid choice once you've outgrown the Easy grids.