Features
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🎯
Four difficulty levels
Easy, Medium, Hard, and Expert — controlled by how many clues are revealed.
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🔀
Local puzzle generation
Every game is a fresh puzzle created on-device, guaranteed to have a single unique solution. No two games are alike.
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⏱️
Time tracking
An elapsed-time clock runs while you play, and your best time for each difficulty is saved between sessions.
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⏸️
Auto-pause
The timer pauses and the board blurs when the app goes to the background, and resumes when you return. Tap the timer to pause manually.
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✏️
Notes / pencil marks
Toggle Notes mode to jot candidate numbers in a cell. Notes clear automatically when the cell's real value is placed.
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💡
Helpful touches
Conflicts highlighted in red, matching digits and the selected row/column/box highlighted, a mistake counter, an Erase button, and a Hint button.
How to Play
- Choose a difficulty from the start screen.
- Tap an empty cell to select it, then tap a number on the pad to place it.
- Fill every row, column, and 3×3 box with the digits 1–9, without repeats.
- Use Notes to pencil in candidates, Erase to clear a cell, and Hint if you get stuck.
- Complete the grid correctly to finish — and try to beat your best time!
Difficulty Levels
- EasyMost clues revealed
- MediumA balanced challenge
- HardFewer clues to start
- ExpertFor seasoned solvers
Frequently Asked Questions
Do I need an internet connection?
No. Puzzles are generated entirely on your device, so the app works completely offline.
Is every puzzle solvable?
Yes. Each puzzle is verified to have exactly one unique solution reachable by logic.
Are my best times saved?
Yes — your best time for each difficulty is stored locally on your device.
Does the app collect any data?
No. Sudoku collects nothing and has no ads or tracking. See the Privacy Policy for details.
Requirements
iOS 17.0 or later on iPhone.