How to Play Sudoku
Simple rules, endless fun
The Sudoku Grid
The board is a 9×9 grid divided into nine 3×3 boxes. Every row, every column, and every box must contain the numbers 1 through 9 — each exactly once.
Alternating shades show the nine 3×3 boxes
How to Play
The Goal
Fill every empty cell so that each row, each column, and each 3×3 box contains all numbers from 1 to 9 — with no repeats.
Select a Cell
Tap any empty white cell on the board to select it. It will turn blue to show it's selected. The row, column, and box it belongs to will be highlighted.
Enter a Number
Tap a number on the number pad at the bottom to place it in the selected cell. Blue numbers are ones you placed; bold black numbers are the given clues.
Erase a Number
Made a mistake? Tap the Erase button to remove the number from the selected cell. Only numbers you placed can be erased.
Notes Mode
Tap the Notes button to enter notes mode. In notes mode, tapping a number adds or removes a small candidate note in the cell — great for tracking possibilities.
Undo & Redo
Made a mistake? Tap Undo to take back your last move. Changed your mind? Tap Redo to put it back. You can undo as many moves as you like.
Hints
Stuck? Tap the Hint button to reveal one correct answer. The hint counter shows how many hints you've used. Using fewer hints is a badge of honor!
Winning
When every cell is correctly filled, the game celebrates your success! You'll see your completion time. Then you can start a new puzzle.
💡 Helpful Tips
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Start with rows, columns, or boxes that already have many numbers filled in.
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If a number can only go in one cell within a row, column, or box — put it there!
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Use notes to mark possible candidates when you're not sure.
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The bold, darker numbers are the starting clues and cannot be changed.
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There's always one correct solution — no guessing required.