Six difficulty levels
From Beginner to Master. Beginner and Easy puzzles can be solved with simple techniques; harder levels give you fewer clues.
Sudora: Sudoku Puzzle
Classic Sudoku, calm and clear.
Sudora is a clean, offline Sudoku game with six difficulty levels, a daily challenge calendar and the tools you expect: notes, undo, highlights and gentle hints. Every puzzle is generated on your device and has exactly one solution.
Sudora is being prepared for release on Android. Store links will be added here when the listing is live.
Illustration of a Sudoku grid with a selected cell, highlighted row, column and box, and pencil notes.
Everything you need, nothing you don't
Sudora focuses on the classic 9×9 puzzle and the small details that make solving pleasant.
Daily challenge
A new puzzle every day with a monthly calendar, current and best streaks, and the option to play or replay past days.
Notes that keep up
Pencil in candidates, and Sudora removes matching notes from the row, column and box when you place a digit.
Three free hints a day
Stuck? A hint reveals one cell. You get three free hints every day, and you can choose to watch an optional video for one more.
Undo, redo and erase
Step back through your moves freely. Highlights for the selected row, column, box and matching digits help you spot patterns.
Your rules
Turn auto-check, the three-mistake limit, the timer and highlights on or off. Long-press a number to fill it quickly across the grid.
Detailed statistics
Games played and won, win rate, best and average times, best score, perfect wins and win streaks for each difficulty.
Light and dark themes
Follow your system setting or pick light or dark, with sound, vibration and keep-screen-on options.
Plays offline
Puzzles are generated on your device and games are saved automatically, so you can continue any time, with or without a connection.
A few quiet minutes, well spent
Sudoku needs no maths, only logic and a little patience. Sudora is designed for short breaks and longer sessions alike, and it stays out of your way while you think.
Short breaks
A Beginner or Easy puzzle fits a coffee break, and your progress is saved if you are interrupted.
A daily habit
The daily challenge gives you one shared puzzle per day and an optional reminder at a time you choose.
Steady progress
Move up through the levels and watch your times and win streaks improve in the statistics.
No pressure
Switch off the timer or the mistake limit whenever you prefer a relaxed game.
How to play
The grid has 9 rows, 9 columns and 9 boxes of 3×3 cells. Fill every empty cell with a digit from 1 to 9 so that each row, each column and each box contains every digit exactly once.
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Pick a cell, then a number
Tap an empty cell and tap a digit on the number pad to place it.
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Pencil in candidates
Turn on Notes to mark the digits a cell could hold. Tap a digit again to remove the note.
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Fill faster
Long-press a number to lock it, then tap cells to place that number quickly.
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Change your mind
Undo and Redo step through your moves, and Erase clears a cell.
Good to know
- Every puzzle has one solution that can be reached by logic alone.
- Hints are permanent. A revealed cell stays revealed; Undo only reverses your own moves.
- Mistakes: with auto-check on, a wrong digit counts as a mistake. After three mistakes the game ends, unless you turned the limit off.
- Autosave: leave at any time and continue later from Home.
- Keyboard support on the desktop build: digits 1–9, arrow keys, Backspace, N for notes and Ctrl+Z / Ctrl+Y.
About ads in Sudora
Sudora is free to play and supported by ads from Google AdMob on Android. We keep them out of the way of the puzzle.
Optional videos you choose
- Watch a short video for one extra hint after your three free daily hints are used.
- Watch a video for a second chance after the mistake limit (once per game).
- Watch a video to double your score on the result screen.
- Rewards are given only when the video is completed. Declining never blocks the game.
Never mid-puzzle
- No banner ads, and no full-screen ads while you are solving.
- An occasional full-screen ad may appear after you finish a puzzle and tap Continue, at most once every few minutes and never in your first session.
- Where required by law, you are asked for consent before personalised ads, and you can change your choice in Settings › Privacy options.
- The desktop build shows no ads.
Privacy, plainly
- No account. Sudora has no sign-up and asks for no name, email or contacts.
- Your game stays on your device. Progress, statistics and settings are stored locally. On Android they may be included in your own device backup.
- Ads involve Google. On Android, the Google Mobile Ads SDK processes some device data, such as the advertising ID and IP address, to show and measure ads. The Privacy Policy explains what and why.
- No analytics or tracking by us. Sudora contains no analytics or crash-reporting SDK, and this website uses no cookies or trackers.