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Fill the 9×9 grid so that every row, column, and 3×3 box contains the digits 1–9 exactly once. Tap an empty cell to select it, then tap a number from the panel to fill it in. Use pencil mode to jot down candidate numbers without committing to an answer.

One Sudoku offers four levels: Easy, Medium, Hard, and Expert. Easy puzzles have more given numbers and are great for beginners. Expert puzzles require advanced techniques and are suited for experienced solvers.

Tap the pencil icon in the toolbar to toggle notes mode. In notes mode, tapping a number adds it as a small candidate note inside the cell without committing it as a final answer. Toggle back to normal mode to enter final answers.

Tap the undo button (↩) in the toolbar to step back one move at a time. You can undo as many times as you like.

A fresh puzzle is available every day — the same puzzle for every player worldwide. Completing it extends your daily streak. Miss a day and your streak resets. The daily challenge never shows interstitial ads, even for free users.

Free users receive 3 hints per day (they reset at midnight). Tap the hint button and the app will highlight the best cell to work on next and reveal its correct value. If you run out of hints, you can watch a short ad for an extra hint or upgrade to Premium for unlimited hints.

Premium removes all ads and gives you unlimited hints. Pricing: $2.99/month, $19.99/year (includes a 3-day free trial), or $39.99 as a one-time lifetime purchase. Prices are shown in your local currency in the App Store.

Open iOS Settings → tap your name at the top → Subscriptions → One Sudoku → Cancel Subscription. You will retain Premium access until the end of the current billing period. Apple handles all subscription billing — we cannot process cancellations directly.

Open One Sudoku, go to Settings inside the app, and tap "Restore Purchases". Your Premium status will be restored as long as you are signed in with the same Apple ID used for the original purchase.

Ads allow us to keep the core game completely free. A short interstitial ad may appear after every 5 completed games. No ads ever appear during gameplay or after a Daily Challenge. You can remove all ads permanently by upgrading to Premium.

Your game data is stored locally on your device. If you have iCloud Backup enabled in iOS Settings, your data is included in your backup and will be restored when you reinstall the app or switch to a new device.

One Sudoku is available in English, Turkish, Spanish, German, and French. The app automatically uses your device language. You can also change the language manually in the app's Settings.

Go to Settings (gear icon) inside the app and tap "Reset All Progress". This clears all statistics, streaks, and completed puzzles. This action cannot be undone.

Yes. Puzzles are generated on-device, so you can play anywhere without an internet connection. The only feature that requires connectivity is loading ads for free users.