
Killer Sudoku
Play Killer Sudoku online free. Cage sum puzzle with four difficulty levels, daily challenge, notes, hints, undo, timer and stats.
Play nowSudoku, kakuro, arithmetic and numbers — mental maths on a clean board.

Play Killer Sudoku online free. Cage sum puzzle with four difficulty levels, daily challenge, notes, hints, undo, timer and stats.
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Play KenKen (MathDoku) puzzle online free. Fill grids with numbers 1-N where each row and column has no repeats, and cages combine to target numbers using math operations.
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Play Crossmath puzzle online free. Fill numbers into a crossword-style grid so both horizontal and vertical math equations are correct. Multiple difficulty levels, daily challenge, and hints.
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Play Palindrome Sudoku free online. Standard Sudoku plus grey mirror lines where digits must read the same forwards and backwards. 27 unique-solution puzzles from Beginner to Master.
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Play Jigsaw Sudoku free online. Instead of 3x3 boxes, the grid is divided into 9 irregularly-shaped jigsaw regions. Each row, column, and region must contain each digit exactly once. 27 unique-solution puzzles from Begin
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Play Nerdle free online! Guess the hidden math equation in 6 tries with color-coded hints. Daily challenge plus 30 progressive levels from simple addition to complex mixed operations.
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Play Sandwich Sudoku free online. Standard Sudoku rules plus outside clues: each number gives the sum of the digits strictly between the 1 and the N in that row or column. 27 hand-crafted levels across six tiers.
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Play Greater-Than Sudoku free online. Standard Sudoku plus greater-than and less-than signs between adjacent cells: the open jaw of each sign points toward the larger digit. 27 unique-solution puzzles from Beginner to Ma
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Play Arrow Sudoku free online. Solve 27 sum-path puzzles where each circled digit equals the sum of the digits along its arrow. Beginner to Master tiers.
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Play Outside Sudoku free online. Standard Sudoku plus outside clues that tell you which digits appear in the border cells of each row and column. 27 unique-solution puzzles from Beginner to Master.
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Play Anti-Knight Sudoku free online. Standard Sudoku plus the knight-move rule: no two cells a knight's move apart (an L-shape of 2+1 squares, like a chess knight) may share a digit. 27 unique-solution puzzles from Begin
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Play X-Sudoku (Diagonal Sudoku) free online. Standard Sudoku plus both main diagonals must contain 1-9 exactly once. 27 hand-crafted levels across six tiers.
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Play Kropki Sudoku free online. Standard Sudoku rules plus outside clues: each number gives the sum of the digits strictly between the 1 and the N in that row or column. 27 hand-crafted levels across six tiers.
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