Sudoku — endless logic puzzles with a guaranteed unique solution
A classic logic puzzle where you fill every row, column, and 3×3 box with the digits 1 to 9 without repeats. Each puzzle is generated fresh the moment you start, and every one has exactly one solution, so you can always solve it with pure logic instead of guessing. It is a great pick for a quick mental break or a bit of brain exercise on the go.
How to use
- Choose Easy, Normal, or Hard. Fewer given numbers means a tougher puzzle.
- Tap an empty cell, then enter a value with the number pad or keys 1 to 9.
- Remove a wrong entry with the ⌫ button or Backspace.
- Fill all 81 cells correctly and completion is detected automatically.
Features & tips
- Selecting a cell dims its row, column, and box, and highlights matching numbers so patterns stand out.
- Any number that breaks the rules gets a wavy underline instantly, helping you catch mistakes early.
- Use the arrow keys to move between cells for fast, mouse-free input.
- Watch the timer at the top and try to beat your best solving time.
FAQ
Q. Is there really only one solution? A. Yes. The generator removes numbers only while verifying that a single solution remains, so every puzzle is unique.
Q. Are pencil marks or notes supported? A. There is no dedicated notes mode, but the matching-number highlight and wavy underline make candidates easy to reason about.
Q. Is my progress saved? A. Progress is not stored; pressing New Game starts a completely fresh puzzle.
