Goal
Fill the 9×9 grid so that every row, every column and each
of the nine 3×3 boxes contains the digits 1–9 exactly once.
Controls
- Click (or tap) an empty cell to select it.
- Press a number on the on-screen pad, or type 1–9 on your keyboard.
- Use Erase, 0, Backspace or Delete to clear your entry.
- Arrow keys move the selection around the grid.
- The pre-filled dark digits are fixed clues and cannot be changed.
Mistakes & hints
- Placing a digit that conflicts with the solution counts as a mistake and is shown in red. After 3 mistakes the game ends.
- Hint reveals the correct value for the selected cell. You get 3 hints per puzzle.
Difficulty levels
- Easy — more starting clues (~40 given), gentle deductions.
- Medium — fewer clues (~32 given).
- Hard — the fewest clues (~26 given), requiring careful logic.