Sudoku.io – Free Online Sudoku Puzzle Game

Sudoku.io is a free browser-based sudoku game with a neon dark theme, four difficulty levels, and a scoring system that rewards speed and accuracy. No download, no account, and no sign-up required — just open the page and start solving. Your progress and high score are saved automatically on your own device.

About This Game

Every puzzle is generated fresh with exactly one valid solution, so you never have to guess — the answer can always be reached by logic alone. Four difficulty levels control how many starting clues you get, and harder puzzles are worth more points per correct answer.

Correct answers chain together into a combo multiplier that decays if you take too long, so accurate, confident play scores far better than fast guessing. Mistakes cost a life. You also get one hint per puzzle, which reveals the correct digit for your selected cell but awards no points for it.

Learn More

New to the game? Our complete beginner's guide to sudoku walks through the grid, the rules and how to make your first moves. Already comfortable with the basics? The sudoku strategies guide covers naked and hidden singles, naked pairs, pointing pairs, box-line reduction and the X-Wing — the techniques that make Hard and Extra Hard puzzles solvable without guessing.

You can also read more about Sudoku.io and how its puzzles are generated, or check the privacy policy.