Sudoku
Test your logical thinking with this beautifully designed Sudoku puzzle game. Every puzzle is uniquely generated with a guaranteed single solution. Choose from three difficulty levels — Easy, Medium, or Hard — and use pencil notes, hints, and undo to work through each challenge. Highlights show conflicts instantly, and the number pad tracks which numbers are complete. Features a mistake counter, timer, and score system that rewards speed and accuracy. Perfect for quick brain training sessions or extended puzzle solving.
How to Play
How to Play:
- Fill the 9×9 grid so every row, column, and 3×3 box contains digits 1–9
- Tap a cell, then tap a number to place it
- Use Pencil mode to add candidate notes
- Three mistakes and the game is over
Controls:
- Click/Tap: Select a cell
- Number Pad: Place a digit
- Pencil button: Toggle notes mode
- Hint button: Reveal one correct cell
- Undo button: Reverse last action
- Arrow Keys: Navigate cells (desktop)
Tips:
- Start with rows, columns, or boxes that have the most filled cells
- Use pencil notes to track possible candidates
- Look for "naked singles" — cells where only one number is possible
- Conflicts highlight in red to help catch mistakes early
- Completed numbers dim on the number pad so you know what's done
Frequently Asked Questions
How do you play Sudoku?
Fill every row, column, and 3×3 box with the numbers 1 through 9. Each number can appear only once in each row, column, and box. Tap a cell to select it, then tap a number to place it. Use logic and elimination to find the correct placement for each number.
What difficulty levels are available?
Three levels: Easy (38 clues), Medium (30 clues), and Hard (24 clues). Every puzzle is uniquely generated with a guaranteed single solution. Higher difficulty means fewer starting clues and more complex logic required.
What are pencil notes in Sudoku?
Pencil notes let you mark candidate numbers in a cell before committing to a final answer. Toggle pencil mode with the pencil button, then tap numbers to add or remove candidates. Notes are automatically cleared when you place a final number in the same row, column, or box.
Is Sudoku free to play?
Yes! Sudoku is completely free to play online with no downloads or registration. Features unique puzzle generation, three difficulty levels, pencil notes, hints, undo, and a clean dark interface optimized for desktop and mobile.
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