Free Printable Hard Sudoku X
A freshly generated hard Sudoku X — diagonal challenge with fewer givens, full A4 sheet.
Sudoku XFree printable hard Sudoku X puzzles — the diagonal-constraint challenge with the gloves off. With 22–25 givens and the diagonal rule running alongside the standard sudoku constraints, you'll need hidden pairs, naked triples, X-Wing, and diagonal-aware versions of the box-line family.
Sudoku X has its own technique cluster — X-cycle on a diagonal, pointing pair across a diagonal — that you only meet at this tier. The Unique Rectangle technique gets a new flavour when the rectangle straddles both diagonals through the centre cell. The /strategies guides walk through the underlying techniques.
Plan on 25–45 minutes with full pencil marks. Print full-page. Every puzzle is uniquely solvable by pure logic; no guessing required. Free, no account, no watermark, freshly generated every load.
Frequently asked questions
Quick answers about printing sudoku from Sudoku247Online.
- What is Sudoku X and how does it differ from classic?
- Sudoku X uses the same 9×9 grid and the same row, column, and 3×3 box rules as classic — plus two extra constraints: each of the two main diagonals (top-left to bottom-right and top-right to bottom-left) must also contain the digits 1–9 exactly once. The cells on those diagonals are picked out with a subtle background tint so the constraint is visible at a glance.
- Why is the printed grid lightly shaded along two diagonals?
- The shade marks the two main diagonals that carry the extra Sudoku X constraint. Pencil marks and digits stay crisp on top of the tint — it's just a visual aid for the diagonal rule, not a hint about the solution.
- Is Sudoku X harder or easier than classic at the same clue count?
- A touch easier at the same clue count — the diagonal eliminations open up more deductions than classic does, so technique chains run shorter. Our difficulty ladder shifts down a notch to compensate: easy Sudoku X has ~34 givens vs ~36 on classic easy; expert is in the 20–22 range.
- How long does a Sudoku X take to solve?
- Easy 8–15 minutes, medium 15–25, hard 25–45, expert often 30–60 minutes. The diagonals tighten the average solve time vs Classic at the same tier once you're scanning them fluently.
- What techniques are essential for Sudoku X?
- Every classic technique transfers directly. The variant adds diagonal-aware versions: pointing pair on a diagonal, X-cycle on a diagonal, naked pair confined to one diagonal. The Unique Rectangle technique gets a new flavour when the rectangle straddles both diagonals through the centre cell.
- Are the solutions printed with the puzzle?
- Not on the standalone Sudoku X printables yet — solving online at /sudoku-x reveals the solution on completion. A 'Print with solutions' option is on the roadmap alongside the killer and jigsaw follow-ups.