Welcome to our free online Sudoku game! Immerse yourself in this captivating logic-based number placement puzzle that has entertained millions worldwide. Whether you're a beginner looking to learn or an expert seeking a challenge, our Sudoku game offers multiple difficulty levels and helpful features to enhance your solving experience.
Choose from Easy, Medium, or Hard puzzles to match your skill level and challenge yourself gradually.
Use pencil marks, hints, and mistake highlighting to improve your solving strategy.
Monitor your solving time and track your improvement over time.
1 Fill each empty cell with a number from 1 to 9. The game starts with some numbers already filled in as clues.
2 Each horizontal row must contain all numbers from 1 to 9, with no duplicates. This tests your ability to think horizontally.
3 Each vertical column must contain all numbers from 1 to 9, with no duplicates. This challenges your vertical thinking patterns.
4 Each 3x3 box (marked by darker borders) must contain all numbers from 1 to 9, with no duplicates. This tests your ability to think in sections.
Scanning Technique Systematically scan rows, columns, and boxes to identify where specific numbers can or cannot be placed. This is particularly effective when starting a new puzzle.
Single Candidate Method Look for cells that can only contain one possible number based on the surrounding numbers. This is often the most reliable way to make progress.
Pencil Marking Use the pencil mark feature to note possible numbers in each cell, helping you track potential solutions and eliminate impossibilities.
Hidden Pairs/Triples Look for cells where only two or three numbers can appear, helping eliminate other possibilities in related cells.
X-Wing Strategy Identify patterns where a number appears in only two positions in two different rows or columns, creating a rectangle pattern.
Swordfish Technique An advanced pattern involving three rows or columns where a number appears in only three positions.
Perfect for learning the basics. Features more starting numbers and requires only simple solving techniques.
Requires more advanced techniques and fewer starting numbers. Good for developing solving skills.
Minimal starting numbers and requires advanced solving techniques. True test of Sudoku mastery.
A: Yes, our Sudoku game is completely free to play with no hidden costs or in-app purchases. You have full access to all difficulty levels and features without any payment required.
A: Yes, the game automatically saves your progress in your browser's local storage. You can safely close the browser and return later to continue where you left off. However, clearing your browser data will reset your progress.
A: To use pencil marks, click the pencil icon or press the 'P' key to toggle pencil mode. In this mode, numbers you enter will appear as small notes in the cells. This is useful for tracking possible numbers while solving the puzzle.
A: If you're stuck, you have several options:
A: Yes, our puzzles are randomly generated using advanced algorithms that ensure each puzzle has a unique solution. The difficulty levels are carefully calibrated to provide consistent challenges appropriate for each skill level.
A: While the game requires an internet connection for initial loading, once loaded, you can continue playing your current puzzle even if your connection drops. However, starting a new puzzle will require an internet connection.
A: Completion time varies by difficulty level and player experience:
A: Yes, you can enable the 'Highlight Mistakes' feature in the game settings. When activated, incorrect numbers will be highlighted in red, helping you identify and correct errors as you play.
A: While our game focuses on individual play, you can compare your completion times with the global averages shown for each difficulty level. This gives you a sense of how your solving skills compare to other players worldwide.
A: Yes, we offer several keyboard shortcuts to enhance your playing experience: