🔢 Sudoku

How to play

Fill the 9x9 grid with the digits 1 through 9. Every row, every column, and every 3x3 box has to contain each digit exactly once, and no digit twice.

Difficulty levels

Easy starts with plenty of givens and solves with straight logic. Medium asks you to scan a little harder. On Hard and Expert you have to eliminate candidates square by square to make progress. Every puzzle has exactly one solution.

The helper buttons

Check turns any misplaced digit red. New game generates a fresh puzzle at the same difficulty. Puzzles are built in your browser on the spot, so you will never run into the same grid twice.

Stare at one puzzle long enough and you stop seeing the obvious squares. Step away for a couple of minutes and the answer usually turns up faster than it would have. On the harder levels, jotting down candidates is close to mandatory.

Why sudoku?

Sudoku is the perfect break in the middle of a loud game night, or a quiet way to fill an evening on your own. No opponent needed, no timer, no pressure: put it down whenever you want and pick it back up later. Working one stubborn square out together also turns it into a surprisingly good two-player puzzle.

Picking a level

On easy the numbers almost announce themselves. On medium and hard you advance by ruling options out, and on expert you really do need to track possibilities. If you are new to it, finish a few easy grids first and then climb.

The game is completely free, needs no sign-up, and runs in your phone's browser. The supply of puzzles never runs out.