Explore dozens of Sudoku variations - from Killer and Samurai to Diagonal and Jigsaw - each adding unique twists to the classic format.
Beyond the classic 9x9 grid lies a world of Sudoku variants, each adding unique twists to the fundamental logic puzzle. From Killer Sudoku with cage sums to Samurai Sudoku with five overlapping grids, these variants offer fresh challenges for solvers of every level. Whether you want arithmetic, visual constraints, or massive grids, there is a Sudoku variant that matches your interests.
All Sudoku variants share the same core principle: use logic to fill cells with no repeated digits in any row, column, or box. What changes is the additional constraints layered on top. These extra rules create entirely new solving strategies and dramatically expand the depth of the puzzle.
The standard and most widely recognized form of Sudoku. A 9x9 grid is divided into nine 3x3 boxes. The solver must fill every cell so that each row, column, and box contains the digits 1 through 9 exactly once. Rules: Fill each row, column, and 3x3 box with digits 1-9 without repetition. Each puzzle has exactly one valid solution determined entirely by logic. Difficulty: Beginner to Expert.
Scaled-down versions of classic Sudoku designed for beginners and younger players. The 4x4 grid uses digits 1-4 with 2x2 boxes, while the 6x6 grid uses digits 1-6 with 2x3 or 3x2 boxes. These smaller puzzles introduce the core logic without overwhelming new solvers. Rules: Same rules as classic Sudoku but on a smaller grid. Difficulty: Beginner.
Killer Sudoku combines elements of Sudoku and Kakuro. The grid features dotted-line cages, each labeled with a target sum. Digits within a cage must add up to that sum, and no digit may repeat within a single cage. No givens are provided - the cage sums are your only clues. Rules: Standard Sudoku rules apply. Additionally, digits in each cage must sum to the indicated total, and no digit may repeat within a cage. Difficulty: Intermediate to Expert.
Samurai Sudoku consists of five overlapping 9x9 grids arranged in an X pattern. The overlapping regions must satisfy the constraints of both grids they belong to, creating a massive puzzle that typically contains 369 cells and requires significant time and concentration. Rules: Each of the five individual grids follows standard Sudoku rules. Overlapping boxes must be valid within both grids simultaneously. Difficulty: Advanced.
Diagonal Sudoku adds two extra constraints to the classic format. In addition to the standard row, column, and box rules, each of the two main diagonals - from corner to corner - must also contain the digits 1 through 9 without repetition. Rules: Standard Sudoku rules apply, plus both main diagonals must contain digits 1-9 exactly once. Difficulty: Intermediate.
Also known as Windoku or NRC Sudoku, Hyper Sudoku overlays four additional 3x3 shaded regions onto the classic 9x9 grid. These extra boxes provide additional constraints and are usually highlighted in a different color to distinguish them from the standard boxes. Rules: Standard Sudoku rules apply. Four additional interior 3x3 boxes must also contain digits 1-9 without repetition. Difficulty: Intermediate.
Jigsaw Sudoku replaces the standard rectangular 3x3 boxes with irregularly shaped regions. Each region still contains nine cells and must hold the digits 1-9, but the unpredictable shapes force solvers to think differently about how constraints interact. Rules: Fill each row, column, and irregular region with digits 1-9 exactly once. Difficulty: Intermediate to Hard.
Greater Than Sudoku removes all given digits and replaces them with inequality signs (< and >) between adjacent cells. These relational clues indicate which of two neighboring cells holds the larger value, requiring solvers to combine ordering logic with standard Sudoku deduction. Rules: Standard Sudoku rules apply with no pre-filled numbers. Inequality symbols between cells indicate relative value. Difficulty: Intermediate.
Thermometer Sudoku features thermometer-shaped lines drawn across the grid. Digits along each thermometer must increase from the bulb (rounded end) toward the tip. This constraint adds a sequential ordering element that interacts with standard Sudoku logic. Rules: Standard Sudoku rules apply. Digits on each thermometer must strictly increase from bulb to tip. Difficulty: Intermediate to Hard.
In Sandwich Sudoku, clues are given outside the grid indicating the sum of the digits that appear between the 1 and the 9 in that row or column. Solvers must determine where the 1 and 9 are placed and which digits are 'sandwiched' between them. Rules: Standard Sudoku rules apply. External clues indicate the sum of all digits located between the 1 and 9 in the corresponding row or column. Difficulty: Hard.
Arrow Sudoku places arrows on the grid. The digit in the circle at the base of each arrow must equal the sum of the digits along the arrow's shaft. Arrows can bend and vary in length, creating complex mathematical relationships throughout the puzzle. Rules: Standard Sudoku rules apply. The circled cell at each arrow's base must equal the sum of all digits along that arrow's line. Difficulty: Hard to Expert.
Exploring Sudoku variants sharpens your logical thinking in new ways. Each variant introduces constraints that force you to approach puzzle-solving from fresh angles. If you have mastered standard Sudoku strategies, variants provide the perfect next challenge without requiring entirely new skills.
Variants are also featured prominently in competitive Sudoku. The World Sudoku Championship tests solvers on a wide array of types, making familiarity with variants essential for aspiring competitors. Even if competition is not your goal, variants keep puzzling engaging and prevent the routine that can develop after solving thousands of classic puzzles.
If you are new to Sudoku, start with the classic 9x9 format and learn the fundamental rules. Once you can solve easy and medium puzzles confidently, Diagonal Sudoku offers a gentle introduction to variant constraints.
For players who enjoy arithmetic, Killer Sudoku and Sandwich Sudoku blend number logic with addition skills. If spatial reasoning is your strength, try Jigsaw or Samurai Sudoku. Those who appreciate sequential logic will find Thermometer and Arrow Sudoku particularly rewarding.
Ready to test your skills? Try our difficulty-graded puzzles: Easy, Medium, Hard, or Expert.
Classic 9x9 Sudoku is the best starting point for beginners. Once comfortable, Mini Sudoku (4x4) is great for young children, while Diagonal Sudoku adds a gentle extra challenge for those ready to advance.
Samurai Sudoku and Arrow Sudoku are generally considered among the most difficult variants. Samurai Sudoku is challenging due to its sheer size (five overlapping grids), while Arrow Sudoku requires complex arithmetic reasoning alongside standard logic.
Yes, many core strategies like naked singles, hidden singles, and elimination apply across all variants. However, each variant introduces unique constraints that require adapted or additional techniques specific to that format.
Many puzzle books, websites, and apps offer variant Sudoku puzzles. Competitive Sudoku championships also feature a variety of Sudoku types, and online communities regularly share free variant puzzles.
Yes. The World Sudoku Championship, organized by the World Puzzle Federation, features a wide range of Sudoku variants including Killer, Diagonal, Jigsaw, Thermometer, and many others alongside classic Sudoku.
Killer Sudoku is widely considered the most popular variant. It combines classic Sudoku logic with arithmetic cage constraints, making it accessible to standard Sudoku solvers while adding a fresh challenge.
Variant Sudoku rewards players who understand the underlying logic. Build that foundation with our strategies guide and the Sudoku glossary, including individual term pages for candidate, house, row and column, naked pair, singles, crosshatching, and X-Wing.
Curious how variants stack up against other puzzles? Read Sudoku variants explained, Sudoku with letters, evil Sudoku, blank Sudoku grid templates, and our comparisons with Kakuro, KenKen, Nonogram, and Minesweeper. For unusual puzzles, see the hardest Sudoku ever and the fastest Sudoku solve records, plus the history of Sudoku world championships and Sudoku world records.
Variant practice also pairs naturally with audience-specific guides like Sudoku for adults, Sudoku for students, Sudoku for teachers, Sudoku for couples, Sudoku for travelers, and Sudoku for programmers.
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