What is Outside Sudoku?

Outside Sudoku (also called Marginal Sudoku) is a Sudoku variant where digits listed outside the grid tell you which numbers appear in the nearest cells of each row or column. Standard Sudoku rules still apply — each row, column and box must contain each digit exactly once.

How do I play Outside Sudoku?

Fill the grid so every row, column and box contains each digit exactly once. The outside clues constrain which digits can go in the border cells: a digit listed on the left of a row must appear in the first few cells of that row, and similarly for right, top and bottom clues.

Is Outside Sudoku free?

Yes. Outside Sudoku on GameZipper is 100% free to play in your browser with 27 puzzles across Beginner to Master tiers. No download or sign-up required.

How many levels does Outside Sudoku have?

There are 27 hand-crafted levels across six tiers: Beginner, Easy and Medium use a 6x6 grid, while Hard, Expert and Master use the classic 9x9 grid. Each puzzle has a unique solution verified by an independent solver.

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Outside Sudoku

Fill the grid · outside clues reveal border digits · 27 unique puzzles

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Outside Sudoku

Standard Sudoku — but outside clues reveal border digits

Outside Sudoku

Outside Sudoku

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