Coffee Sudoku is a cozy sudoku app with classic, killer, daily, and zen modes — no ads, no paywalls, plays fully offline.

Pour a coffee, pick a difficulty, and solve. Every puzzle is verified to have exactly one solution. Keep your daily challenge streak going, beat your fastest time, and explore harder modes as you improve.

Modes

- Daily Challenge — one fresh classic 9x9 puzzle every day
- Classic Sudoku — Easy, Medium, Hard, Very Hard
- Killer Sudoku — Easy, Medium, Hard, Very Hard cage puzzles, available from day one
- Zen Sudoku — solve at your own pace, no validation, no mistakes counter
- Redacted — a hidden twist on the classic format, unlocked through play

Why Coffee Sudoku

- 100% offline. No internet needed. Ever.
- No ads, no popups, no nags
- Hints in classic and daily modes — they point at the next logical step instead of just filling the answer
- Notes mode (crayon) for working out candidates in any mode
- Daily streaks and personal bests to keep you coming back
- Share any puzzle with a friend via a single link
- Cozy coffee-shop aesthetic, built for relaxed solving

Whether you're new to sudoku or hunting hard killer puzzles, Coffee Sudoku gives you the cleanest, calmest place to play. No accounts. No tracking. Just sudoku.

Long-press a cell to add notes. Tap a clue to highlight all matching numbers. In classic and daily modes, use the hint button if you get stuck.

Killer sudoku fans: cages are randomized per puzzle and rigorously verified for unique solution. All four killer difficulties are available from your first launch.

Privacy: nothing leaves your device. No analytics, no ads SDK, no tracking. Open source spirit, made for puzzle people.