Frequently Asked Questions

Yes! Sudoku is completely free to download and play. The app is supported by occasional advertisements which help us continue improving it.

The app offers four difficulty levels:

• Easy: 46 cells given — great for beginners
• Medium: 36 cells given — a solid everyday challenge
• Hard: 29 cells given — requires careful reasoning
• Expert: 23 cells given — for seasoned solvers only

Every day, a unique Sudoku puzzle is generated. All players get the same puzzle for that day. Complete daily challenges on consecutive days to build a streak!

You can undo any move — whether entering a number, erasing a cell, or toggling a memo. There is no limit to how many times you can undo. You can also redo any undone action.

Memo Mode lets you write small candidate numbers inside a cell, just like pencil marks on a paper puzzle. Tap the Memo button to toggle this mode on or off. When you enter a final number into a cell, its memos are automatically cleared.

Each game starts with 3 hints. Tapping the hint button reveals the correct answer for the currently selected cell. Hints cannot be replenished during a game, so use them wisely!

The app allows up to 3 mistakes per game. If you make a third mistake, the game ends. You can restart the same puzzle from scratch at any time.

Yes. Your current game is saved automatically every time you make a move. When you reopen the app, you can continue from where you left off using the "Continue" button on the home screen.

Yes! All puzzles are generated locally on your device. You can play Sudoku without an internet connection. An internet connection may be required for advertisements to load.

For questions, bug reports, or feedback, please email us at leekyusung1031@gmail.com. We aim to respond within 2 business days.