Z Zeloku

Beyond classic · 12 variants

Sudoku variants — every way to play

Same digits, new geometry. Start with a playable variant below, or learn the rules of the famous ones.

Playable here Easy

Mini Sudoku (4×4 & 6×6)

The fastest variant — same logic on a smaller grid. Perfect warm-up and the best first Sudoku for kids.

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Playable here Easy

Kids Sudoku

Gentle 4×4 and 6×6 boards with color-friendly layouts for ages 5–10.

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Rules guide Hard

Killer Sudoku

No givens — dashed cages with sum targets replace starting digits. The 45 rule does the heavy lifting.

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Rules + strategy Medium

Jigsaw Sudoku

Irregular regions replace 3×3 boxes. Same digits 1–9, twisted geometry.

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Rules + strategy Medium

Diagonal Sudoku (Sudoku X)

Both main diagonals must also contain 1–9 — two extra units to track.

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Rules + strategy Hard

Samurai Sudoku

Five overlapping 9×9 grids sharing corner boxes. A marathon, not a sprint.

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Playable here All levels

Classic 9×9

The original: rows, columns, boxes. Every variant builds on these three rules.

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Explained Medium

Hyper Sudoku (Windoku)

Four extra shaded 3×3 regions inside the classic grid, each also holding 1–9.

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Explained Easy

Wordoku

Letters instead of digits — nine distinct letters spell a hidden word on one row.

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Explained Very hard

16×16 Sudoku

Hexadoku: digits 0–F across a giant grid. Sessions measured in hours.

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Explained Medium

Even/Odd Sudoku

Shaded cells must contain even digits, unshaded odd — free eliminations from move one.

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Explained Medium

Thermo Sudoku

Digits strictly increase along thermometer lines. Great for learning constraint logic.

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How variants make you stronger

Classic Sudoku rewards pattern memory. Variants break those patterns on purpose — Jigsaw hides your usual box scan, Killer removes your givens, Samurai stretches your working memory across five grids. Rotating variants is the closest thing Sudoku has to cross-training: one week of Jigsaw measurably speeds up box scanning on classic boards.

Recommended path: MiniClassic MediumJigsawKillerDiagonal XSamurai.

FAQ

What are the different types of Sudoku?
The main families are: size variants (Mini 4×4/6×6, 16×16), shape variants (Jigsaw, Hyper), constraint variants (Killer, Thermo, Even/Odd), diagonal variants (Sudoku X), and multi-grid variants (Samurai). All share the core rule — each symbol appears once per unit.
Which Sudoku variant is the hardest?
For most players: Samurai by length, Killer by deduction depth, and 16×16 by sheer bookkeeping. 'Hardest' depends on your weakness — Killer punishes weak mental arithmetic, Jigsaw punishes weak spatial tracking.
Which Sudoku variant is best for beginners?
Mini Sudoku 4×4. It teaches rows/columns/regions in under five minutes with zero frustration, and every technique transfers directly to classic 9×9.
Is Killer Sudoku harder than classic Sudoku?
Usually yes at the same rating — Killer starts with no givens, so early progress depends on cage arithmetic (the 45 rule) before classic techniques even apply. Expert classic and Expert Killer are comparable.
Do Sudoku variants help you improve at classic Sudoku?
Yes — variants force you to re-derive eliminations instead of pattern-matching by habit. Players who rotate one variant a week report faster spotting of Hidden Singles and pairs on classic boards.

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