Sudoku Variants

Ten ways to play beyond classic sudoku. Each variant keeps the spirit of the puzzle. fill the grid with logic, no guessing, but bends a rule. Some add new constraints; others change the geometry; some give you extra hints.

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Killer Sudoku

9×9 · Medium to evil

Sudoku meets killer-style arithmetic: every dotted region sums to its total.

6×6

Mini Sudoku (6×6)

6×6 · Beginner to medium

A shorter sudoku for kids, classrooms, and quick five-minute sessions.

Samurai Sudoku

Five overlapping 9×9 grids · Hard to evil

Five 9×9 sudokus joined at the corners. Solve them as one giant puzzle.

Diagonal Sudoku (X-Sudoku)

9×9 · Medium to expert

Classic sudoku plus a constraint on both main diagonals.

Hyper Sudoku

9×9 · Medium to expert

Classic sudoku with four extra 3×3 regions to satisfy.

Jigsaw Sudoku

9×9 · Medium to evil

Sudoku with non-rectangular regions. same digit constraint, weirder shapes.

16×16

Sudoku 16×16

16×16 · Hard to evil

Hexadecimal sudoku for marathon solvers.

12×12

Sudoku 12×12

12×12 · Hard to evil

Twelve-digit sudoku for serious solvers.

23

Even-Odd Sudoku

9×9 · Easy to hard

Classic sudoku with a constraint on which cells hold even or odd digits.

45

Consecutive Sudoku

9×9 · Medium to evil

Classic sudoku with markers showing which adjacent cells differ by exactly one.

4×4

4×4 Sudoku

4×4 · Very easy

The smallest sudoku: a 4×4 grid with digits 1-4. Perfect for kids and total beginners.

SUD

Wordoku

9×9 · Easy to expert

Classic sudoku with letters instead of numbers, sometimes a word appears on a diagonal.

412019

Sandwich Sudoku

9×9 · Medium to expert

Border clues tell you the sum of the digits sandwiched between the 1 and the 9 in each row and column.

28

Thermo Sudoku

9×9 · Medium to expert

Digits must strictly increase along each thermometer, starting from the rounded bulb end.

8

Arrow Sudoku

9×9 · Medium to expert

The digit in each circle equals the sum of the digits along the arrow attached to it.

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Greater Than Sudoku

9×9 · Medium to hard

Inequality signs between neighbouring cells tell you which digit is larger, often with no starting digits at all.

Comparison table

VariantGridKey ruleDifficulty range
Killer Sudoku9×9Cages with sum totals; no repeats in cagesMedium to evil
Mini Sudoku (6×6)6×6Digits 1-6 with 2×3 boxesBeginner to medium
Samurai SudokuFive overlapping 9×9 gridsFive sudokus sharing four corner boxesHard to evil
Diagonal Sudoku (X-Sudoku)9×9Both main diagonals also contain 1-9Medium to expert
Hyper Sudoku9×9Four extra 3×3 regions also contain 1-9Medium to expert
Jigsaw Sudoku9×9Irregular regions replace 3×3 boxesMedium to evil
Sudoku 16×1616×16Digits 0-9 + A-F (hex) in 4×4 boxesHard to evil
Sudoku 12×1212×12Digits 1-12 in 3×4 boxesHard to evil
Even-Odd Sudoku9×9Shaded cells must hold even digitsEasy to hard
Consecutive Sudoku9×9Markers between cells whose digits differ by 1Medium to evil
4×4 Sudoku4×4Digits 1-4, each once per row, column, and 2×2 boxVery easy
Wordoku9×9Nine letters instead of digits; often a hidden wordEasy to expert
Sandwich Sudoku9×9Clues give the sum of digits between the 1 and the 9 in each lineMedium to expert
Thermo Sudoku9×9Digits increase along each drawn thermometer, from the bulbMedium to expert
Arrow Sudoku9×9The circled digit equals the sum of the digits along its arrowMedium to expert
Greater Than Sudoku9×9Inequality signs between cells show which neighbour is largerMedium to hard