Games · Android

Sudoku – Classic Number Puzzle

Offline Sudoku with hints that teach

A free, offline Sudoku app with six difficulty levels, hints that teach real techniques, daily challenges and detailed stats — with no ads and no sign-up.

A NowStacks product · Built by Gemini Digital Solutions

About Sudoku – Classic Number Puzzle

Sudoku – Classic Number Puzzle is the NowStacks take on the world's favourite logic puzzle: free, fully offline, with no ads and no sign-up. Every puzzle has exactly one solution that can be reached by logic alone, graded across six levels — Easy, Medium, Hard, Expert, Master and Extreme — by the techniques it needs.

When you're stuck, a hint shows the next logical step and explains why it works, from Hidden Singles to X-Wings and XY-Wings, so you get better instead of just getting unstuck. A daily challenge with a calendar and streaks gives everyone the same puzzle each day.

Notes and one-tap auto-notes, row/column/box highlighting, switchable mistake checking, unlimited undo and per-level stats support every style of solver. The app collects no data, doesn't request internet access, and supports 15 languages, light and dark mode, six colour themes, tablets, Chromebooks, keyboards and TalkBack. Want more quick brain workouts? Try Brain Games.

What you can do with Sudoku – Classic Number Puzzle

Six difficulty levels
Easy to Extreme, graded by the solving techniques each puzzle needs.
Puzzles that play fair
Every puzzle has exactly one solution and can be solved without guessing.
Hints that teach
Each hint reveals the next logical step and explains the technique behind it.
Daily challenges
One new puzzle a day for everyone, with a calendar, streaks and replays.
Notes and auto-notes
Pencil marks with one-tap auto-notes that clear when you place a number.
Highlights and mistake checking
Row, column, box and matching-number highlights with optional duplicate checking.
Progress stats
Best and average times, win rate, perfect games and streaks for every level.
Made for everyone
Dark mode, six colour themes, tablets, keyboards, TalkBack and 15 languages.