Sudoku Variants
Twelve unique twists on classic sudoku. Every variant is printable as a PDF, available in multiple difficulties, with an optional answer key.
Extra Regions
Diagonal (X-Sudoku)
Both main diagonals must also contain each digit from 1 to 9 exactly once, adding two new constraints on top of the standard rules.
Easy to Very Hard
Hyper Sudoku
Four extra 3x3 regions, each inset one cell from a corner of the grid, must also contain 1-9. The additional regions dramatically constrain the solution space.
Very Easy to Hard
Asterisk Sudoku
A star-shaped set of 9 highlighted cells (the center of each 3x3 box plus its diagonal neighbors) must together contain each digit from 1 to 9.
Easy to Expert
Center Dot
The center cell of each 3x3 box is highlighted. Those nine center cells must collectively contain each digit from 1 to 9 exactly once.
Easy to ExpertLogic Constraints
Even/Odd
Shaded cells enforce parity: grey cells must contain an even digit (2, 4, 6, or 8), and blue cells must contain an odd digit (1, 3, 5, 7, or 9).
Very Easy to Hard
Sandwich Sudoku
Numbers printed outside the grid show the sum of all digits sandwiched between the 1 and the 9 in that row or column. The 1 and 9 themselves are not included in the sum.
Easy to Expert
Kropki
Dots between adjacent cells encode relationships: a white dot means the two digits are consecutive; a black dot means one digit is exactly double the other.
Easy to ExpertStructural
Irregular (Jigsaw)
The nine standard 3x3 boxes are replaced by nine irregular connected regions of varying shapes. Each region must still contain 1-9 exactly once.
Medium to Expert
Killer Sudoku
Cells are grouped into cages, each labeled with a target sum. Fill the grid so every cage sums to its target, with no digit repeated within any cage, row, column, or box.
Expert only
Arrow Sudoku
Each arrow has a circle at its base. The digit placed in the circle must equal the sum of all digits placed along the arrow's shaft.
Easy to Expert
Thermometer
Thermometer shapes are drawn across the grid. Digits must increase strictly from the bulb end to the tip; no two cells on the same thermometer share a digit.
Easy to ExpertMulti-Grid
Samurai Sudoku
Five overlapping 9x9 grids arranged in a cross pattern: one center grid and four corner grids, each sharing a 3x3 box with the center. All five grids must be solved simultaneously.
Easy to Expert