Sudoku Variations Explained: 4×4, 6×6, 9×9, and Beyond
Sudoku isn't just the 9×9 grid you see in newspapers. There are many variations, each with its own rules, difficulty, and target audience. Here's a complete guide to the most common ones.
Standard grid sizes
4×4 Sudoku
The smallest standard variant. Uses digits 1–4 with four 2×2 boxes. Perfect for children ages 4–7. Most puzzles can be solved in 1–2 minutes.
6×6 Sudoku
Uses digits 1–6 with six 2×3 boxes (or 3×2). A natural step up from 4×4. Good for kids ages 7–9 and for adults who want a quick puzzle.
9×9 Sudoku
The classic. Uses digits 1–9 with nine 3×3 boxes. This is what most people think of when they hear "sudoku." Difficulty ranges from easy to evil.
Non-standard grid sizes
5×5 Sudoku
A Latin square variant using digits 1–5. There are no boxes — only row and column constraints. Simpler than 9×9 but harder than 4×4.
7×7 Sudoku
Another Latin square variant, using digits 1–7. No boxes. Rare but interesting for players who want something different.
8×8 Sudoku
Uses digits 1–8 with 2×4 boxes. Less common than 9×9 but a good challenge for players tired of the standard grid.
Popular thematic variants
Killer Sudoku
Instead of given digits, cells are grouped into "cages" with a target sum. You must fill each cage so the digits add up to the target — and no digit repeats within a cage. Significantly harder than standard sudoku.
Jigsaw Sudoku
Also called "irregular sudoku." The 9×9 grid is divided into nine irregular shapes instead of 3×3 boxes. Each shape must contain 1–9 exactly once. Looks wildly different from standard sudoku but follows the same logic.
Diagonal Sudoku
Standard 9×9 rules, plus one extra constraint: both main diagonals must also contain 1–9 exactly once. Adds a bit of difficulty without changing the fundamentals.
Sudoku X
Another name for diagonal sudoku. Sometimes also refers to puzzles with additional diagonal constraints beyond the two main diagonals.
Which variation should you try?
- New to sudoku? Start with 4×4, then 6×6, then 9×9.
- Want a quick puzzle? Try 6×6.
- Want a real challenge? Play 9×9 Evil, then move to Killer Sudoku.
- Want something different? Try Jigsaw or Diagonal sudoku.
What we offer
On our site, you can generate and print sudoku in seven grid sizes:
- 3×3 — the simplest possible puzzle
- 4×4 — great for young children
- 5×5 — Latin square variant
- 6×6 — the sweet spot for beginners
- 7×7 — Latin square variant
- 8×8 — an unusual challenge
- 9×9 — the classic standard
Every puzzle is generated fresh, verified to have exactly one solution, and can be printed with a custom color theme or cartoon design.
← Back to all articles