Sudoku

A classic Sudoku puzzle, generated instantly

Sudoku is a number placement puzzle: fill a 9x9 grid so the logic clicks into place one cell at a time. Every puzzle here is built fresh in your browser the moment you load the page or start a new game, at Easy, Medium, or Hard. It works offline once loaded, and nothing you type is ever sent anywhere.

How to play

Fill the grid so every row, every column, and every 3x3 box contains the numbers 1 through 9 with no repeats. The bold numbers already on the board are givens and can't be changed; tap or click an empty cell and use the number pad (or your keyboard) to fill it in. Turn on notes to pencil in small candidate numbers while you work out a cell, use check to see which entries don't match the solution, or use hint to reveal a cell outright. A puzzle is solved once every cell is filled in correctly.

Is Sudoku free to play?

Yes. It's free, with no account, sign-up, or download needed.

Does it work offline?

Once the page has loaded, the game keeps generating and checking puzzles without an internet connection, since everything runs in your browser.

Are puzzles always solvable with a unique solution?

Yes. Every puzzle is checked as it's built to make sure it has exactly one solution and can be solved through logic alone, with no guessing required.

Is my progress saved?

Yes. Your current puzzle, entries, notes, and timer are saved in your browser as you play, so reloading the page won't lose your place.

Is my data collected?

No. There's no server behind this game. Your progress and preferences are saved only in your own browser, and nothing about the puzzles you play is ever sent anywhere.

Can I play unlimited puzzles?

Yes. Every new game generates a fresh puzzle at your chosen difficulty, so you can keep playing as many rounds as you like.