By Knexio · Updated May 2026
Sudoku is a classic logic-based number placement puzzle. Fill the 9×9 grid so that each row, column, and each of the nine 3×3 subgrids contain all digits from 1 to 9 without repetition.
Each puzzle starts with some numbers already filled in. Fill empty cells with digits 1-9 following these rules: Each row must contain all digits 1-9 without repetition. Each column must contain all digits 1-9 without repetition. Each 3×3 box must contain all digits 1-9 without repetition. Use logic and elimination to determine the correct numbers. Click/tap a cell to select it, then choose a number from the number pad. Use pencil marks for notes to track possible numbers.
Start with cells that have the fewest possibilities. Look for 'naked singles' (cells with only one possible number). Use 'hidden singles' technique (a number that can only go in one cell in a row/column/box). Eliminate possibilities systematically. Take breaks - fresh eyes often spot patterns more easily.
Yes, all games on Knexio are completely free to play. There are no hidden charges, subscription fees, or in-app purchases. We support our games through non-intrusive advertisements.
No downloads required! All our games run directly in your web browser. They work on desktop computers, laptops, tablets, and smartphones. Just visit the page and start playing.
Most games automatically save your high scores and progress in your browser's local storage. Your best scores will be remembered even if you close the browser, as long as you don't clear your browsing data.
Absolutely! All Knexio games are fully responsive and optimized for mobile devices. Touch controls are implemented for games that require precise input. The interface automatically adapts to your screen size.
Most games include optional sound effects. Look for a sound/mute button in the game interface. You can enable or disable sound based on your preference. We keep sound subtle and non-intrusive.
This is a fun browser game that you can play for free. Enjoy this entertaining game with simple controls and engaging gameplay. Our version is built from scratch in vanilla JavaScript, optimized for performance across all devices. The game runs entirely in your browser, with no downloads or installations required. All progress is saved locally in your browser's storage. Like all games on Knexio, This Game is completely free to play. We support our games through non-intrusive advertisements that never interfere with the gameplay experience.