Sudoku:Pure

 Sudoku:Pure is a clean and fully offline classic sudoku puzzle app focused on a pure and distraction-free gaming experience. Generate unlimited unique sudoku puzzles locally on your device with four professional difficulty levels, assist your solving process with smart pencil marks and hint tools, and record your gaming progress and achievements — all without any network connection, advertisement interruptions, or in-app purchases. Designed for casual puzzle players and professional sudoku enthusiasts, Sudoku:Pure delivers a pure logic training experience for offline leisure and brain exercise.

App Features

Unlimited Offline Sudoku Generation: Generate infinite unique 9×9 standard sudoku puzzles entirely through local recursive algorithms. All generated puzzles have only one valid solution to ensure professional gaming quality. Four complete difficulty levels — Easy, Medium, Hard, and Expert — perfectly adapt to beginners, intermediate players and senior sudoku lovers, meeting all daily puzzle challenges.

Smart Pencil Mark & Candidate Assistance: Support professional pencil draft marking mode for advanced solving. freely mark multiple candidate numbers in each grid, and distinguish formal answers with reduced and faded font display. The one-click automatic candidate deduction function can filter all legal optional numbers based on the current board status, helping users sort out solving ideas and improve logical reasoning efficiency.

Real-time Error Highlight & Offline Hints: Built-in real-time rule detection system that automatically highlights conflicting numbers in red when repeated values appear in the same row, column or 3×3 grid. The real-time error reminder can be manually turned off in settings for independent error checking and thinking. Support graded offline step-by-step solving hints, providing targeted guidance without directly revealing the full answer, protecting your puzzle-solving fun.

Complete Game Statistics & Achievement System: Accurately record full game data including single-game duration, best historical record, and pass times of each difficulty. Support perfect clearance achievements for error-free and hint-free customs clearance, encouraging standardized puzzle-solving habits. Built-in calendar check-in function automatically records daily gaming records and continuous check-in streaks, witnessing your growth in logical thinking.

Pure Immersive Gaming Experience: Adopt minimalist iOS native UI design with no advertisements, no pop-up windows, no push notifications and no redundant commercial distractions. Support automatic and manual switching of light and dark modes, native smooth animation and haptic feedback, bringing comfortable and low-fatigue long-term puzzle-solving experience. All game data is stored locally permanently to ensure user privacy security.

Humanized Custom Setting: Provide rich personalized switch settings, including real-time error reminder switch, automatic candidate number switch, sound effect and vibration feedback switch. Support one-click reset of statistical data or full data clearing, allowing users to freely customize the gaming experience and reset progress as needed.

Technical Support

Thank you for downloading Sudoku:Pure. We are committed to providing users with a stable, pure and smooth offline sudoku puzzle experience. If you encounter any technical problems, abnormal display or functional errors during use, please check the relevant instructions below for troubleshooting.

System Requirements

• Platform: Exclusively available on iPhone and iPad, supports iOS 15.0 and above systems.
• Network Environment: Full offline operation. All core functions including puzzle generation, gaming, hints and data statistics can be used normally without internet connection. The app never requests network permissions, uploads user data or synchronizes private information to the cloud.
• Permissions: No sensitive system permissions such as location, camera, microphone, photo library or Bluetooth are required. The app has zero unauthorized access to user private data.
• Performance: It is recommended to update your device to the latest official iOS version to ensure optimal operation fluency, avoid frame drop, stutter or display abnormality.
• Storage: Please reserve enough device storage space to ensure normal saving and reading of local game records, achievement data and user preference settings.

Frequently Asked Questions

The app crashes or freezes while generating puzzles or gaming

Close redundant background applications to release device memory and computing resources. Check whether the device storage space is sufficient. Restart the app or device to clear temporary cache files. If the problem persists, please reinstall the latest version of Sudoku:Pure.

Real-time error highlighting does not take effect

Confirm that the real-time error reminder switch is turned on in the app settings. Exit and re-enter the current game interface to refresh the detection logic. If the function is abnormal, restart the app to fix temporary program logic errors.

Game duration or achievement data is missing

All data is stored locally on the device. Do not forcibly close the app during the game to avoid data saving failure. Normal app updates will not clear local data. If data is lost accidentally, check whether the device system has cleared local cache abnormally.

Dark/Light mode display is abnormal

The skin mode only changes the UI visual style and will not affect any local game data. Manually switch the system light and dark mode again or restart the app to repair visual stuttering and display deviation.

Candidate number auto-derivation function fails

The automatic candidate number function is based on the current valid numbers of the board. When the current grid has confirmed valid numbers or the board is full, the function will be invalid. Clear redundant filled numbers and try again.

Will updating the app delete my game records?

Regular version updates will not clear any local game data, including gaming records, best scores, check-in streaks and unlocked achievements. For major version iterations, it is recommended to back up your device data in advance to avoid accidental data loss.

Contact Support

If you have functional suggestions, bug feedback or technical consultation needs, please contact our support team through the official email:

Support Email: 18389836001@163.com

We will check and reply to all user feedback within 24–48 hours, continuously optimize product experience and fix existing problems. Thank you for using Sudoku:Pure — enjoy pure offline sudoku puzzle time and exercise your logical thinking anytime, anywhere! ✅🧩