About Classic Sudoku
Classic Sudoku is the number puzzle millions solve with their morning coffee, built here with the polish of a premium puzzle app. Fill the nine by nine grid so every row, every column and every three by three box holds the digits one to nine exactly once. Every puzzle is freshly generated and proven to have exactly one solution, then graded by the solving techniques it really needs, so Easy, Medium, Hard and Expert feel genuinely different: Easy flows with simple singles, while Expert asks for pairs, pointing candidates and patient chains of logic. Tap a square and the whole row, column and box light up, together with every copy of the same digit. Switch on Notes to pencil in candidates, and when you place a number the notes it rules out vanish by themselves. Three mistakes are allowed per puzzle, the Hint button explains why a digit belongs where it does, and Undo takes back any step. A fresh Daily Challenge waits every day, shared by every player, and statistics track your best times and winning streaks for each difficulty. Your puzzle saves automatically.
How to play
Tap a square, then tap a number (or type 1–9; arrow keys move). Every row, column and 3×3 box must contain 1–9 once. Notes (N) pencils in candidates, Erase clears a square, Hint (H) explains the next step, Undo (Z). Three mistakes end the puzzle.
Controls
| Click / Tap | Select |
| 1-9 | Place |
| Arrow keys | Move |
Difficulty: ★★☆☆☆ · Released: 2026-10-07