Sudoku Unlimited offers six logic-based difficulties and three unique grid styles. Solve daily puzzles or generate endless boards for free online.
Game Overview
Sudoku Unlimited is a logic puzzle where every move narrows down the possibilities. Fill a 9×9 grid with digits one through nine, making sure each row, column, and 3×3 box contains every digit exactly once. Choose from six difficulty levels, play daily challenges, or generate unlimited puzzles in Classic, Diagonal, and Jigsaw formats. Every board is checked for a unique solution, so you can solve it through logic rather than guesswork.
Game Modes & Navigation Bar
Choose a puzzle format, adjust the difficulty, or explore different ways to play using the top navigation bar.
Modes & Daily Challenges
- Daily: Solve one unique puzzle per difficulty each day and build your winning streak.
- Unlimited: Generate fresh puzzles in your browser whenever you want.
- Archive: Replay past daily puzzles at any difficulty.
- Printable Sheets: Print two to twelve puzzles per page, with an optional answer sheet.
Six Difficulty Levels
Each puzzle is graded by the hardest logical technique needed to solve it, rather than simply counting its starting clues.
- Fast: Solve using basic scanning, usually in four to five minutes.
- Easy: Find straightforward single candidates with a little more searching.
- Medium: Use naked pairs, pointing pairs, and box/line reductions.
- Hard: Apply familiar techniques more frequently, with pencil notes becoming increasingly useful.
- Expert: Recognize advanced patterns such as X-Wings, Y-Wings, and simple colouring.
- Evil: Tackle complex logical chains, including XY-Chains, for a tougher challenge.
- Three Sudoku Variants
- Classic Sudoku: Complete the standard 9×9 grid with nine 3×3 boxes.
- Sudoku X: Follow the classic rules while ensuring both main diagonals also contain digits one through nine without repetition.
- Jigsaw Sudoku: Solve a grid where the regular 3×3 boxes are replaced by nine irregular regions.
How To Play
The board contains 81 cells arranged into nine rows, nine columns, and nine 3×3 boxes.
- Select a Cell: Click or tap an empty cell to choose where to enter a number.
- Enter Digits: Select a digit from the number pad or type it using your keyboard. Entering the same digit again clears the cell.
- Follow the Rules: Each row, column, and 3×3 box must contain the digits one through nine exactly once.
Use the same core rules for Classic Sudoku, then apply the additional diagonal or irregular-region constraints in the other variants.
Controls & Helper Tools
Several optional tools make it easier to track possibilities and work through difficult puzzles.
- Number Pad Counter: Shows how many copies of each digit are still missing from the grid.
- Pencil Notes: Press N or Space, or hold Shift while typing, to enter candidate notes instead of answers.
- Smart Hints: Get step-by-step guidance that identifies a logical pattern and explains why it works before suggesting a move.
Keyboard Shortcuts: Use arrow keys to navigate, Backspace or Delete to clear a cell, U or Ctrl+Z to undo, H for hints, and P to pause and hide the grid.
The hint system also refuses to assist while an uncorrected error remains on the board, helping you avoid building further deductions on a mistake.
Why Play Sudoku Unlimited?
Sudoku Unlimited offers more than a way to pass the time. Each puzzle encourages you to recognize patterns, compare possibilities, and make decisions based on evidence.
- Practice Logical Thinking: Work through deductions instead of relying on random guesses.
- Choose Your Challenge: Start with simple scanning or progress toward advanced solving techniques.
- Play at Your Own Pace: Switch between daily challenges and unlimited puzzles whenever you want.
- Enjoy Free Browser Gameplay: Play without downloading an app or creating an account. Your progress and statistics are stored on your device.
Related Games
Explore these number puzzles and logic games for more brain-teasing challenges
