Continuously play puzzles without stopping. Perfect for long sessions! Complete as many as you can.
No timer, no pressure. Just relax and solve at your own pace. Perfect for mindful puzzle-solving.
Learn Sudoku
Interactive Tutorial
Understanding the Grid
Sudoku is played on a 9×9 grid divided into nine 3×3 boxes. Each row, column, and 3×3 box must contain the numbers 1-9 without repetition.
Starting Strategy
Look for rows, columns, or boxes that already have many numbers filled in. These give you the best clues for where to place the next number.
Using Notes
Use the notes feature to mark possible numbers for each cell. This helps you track multiple possibilities and make logical deductions.
Process of Elimination
If a number can only go in one cell in a row, column, or box, that's where it belongs. Eliminate impossible options systematically.
Solving Techniques
Beginner Techniques
Naked Singles
When a cell can only contain one possible number, fill it in immediately. This is the most basic and essential technique.
Hidden Singles
When a number can only go in one cell within a row, column, or box, even if that cell has other possibilities.
Intermediate Techniques
Naked Pairs
When two cells in a row, column, or box can only contain the same two numbers, you can eliminate those numbers from other cells in that unit.
Pointing Pairs
When a candidate number appears only in one row or column within a box, it can be eliminated from that row or column outside the box.
Box/Line Reduction
If a number in a box is confined to a single row or column, eliminate that number from the rest of the row or column outside the box.
Advanced Techniques
X-Wing
When a candidate appears in exactly two rows and two columns forming a rectangle, you can eliminate that candidate from other cells in those columns (or rows).
Swordfish
An extension of X-Wing using three rows and three columns. Very powerful for Expert-level puzzles.
XY-Wing
A chain of three cells with specific bi-value patterns that allows elimination of candidates in cells that see both endpoints.
Strategy Tips
Start with Easy Wins
Begin by filling in the most obvious numbers. Look for rows, columns, or boxes with the most numbers already filled.
Use Notes Liberally
Don't try to keep everything in your head. Use the notes feature to track possibilities for each cell.
Scan Systematically
Check each number 1-9 in turn, looking for where it can be placed. This systematic approach prevents missing opportunities.
Take Breaks
If you're stuck, pause and come back later. Fresh eyes often spot patterns you missed before.
Focus on Constraints
Look for cells with the fewest possibilities. These are usually the easiest to solve and can trigger chain reactions.
Practice Daily
Regular practice improves pattern recognition. Start with Easy puzzles and gradually increase difficulty.
Common Mistakes to Avoid
Guessing Too Early
Avoid guessing unless absolutely necessary. Use logical deduction and techniques first. Guessing can lead to cascading errors that are hard to fix.
Not Updating Notes
When you fill in a number, remember to remove it from notes in all related cells (same row, column, and box). Outdated notes lead to mistakes.
Rushing Through Easy Numbers
Even obvious placements should be double-checked. A single mistake early on can make the puzzle unsolvable later.
Ignoring Patterns
Advanced techniques exist for a reason. Learn to recognize patterns like pairs, triples, and pointing pairs to solve harder puzzles.
Playing Above Your Level
Start with easier difficulties and work your way up. Jumping to Expert too quickly leads to frustration and bad habits.
Practice Puzzles
Ready to practice? Go back to the Play tab and select your difficulty level!
Your Statistics
Storage: All your stats are saved locally in your browser and persist forever.
Lost if: You clear browser data, use incognito mode, or switch browsers/devices.
Privacy: Your data stays on your device - nothing is sent to any server.
Player Level
Daily Challenge
Puzzle Collections
Personal Records
Progress Overview
Total Games Played
Games Won
Win Rate
Average Time
Performance by Difficulty
Easy
Medium
Hard
Expert
Achievements
First Victory
Complete your first puzzle
Speedster
Complete a puzzle in under 5 minutes
Perfect Game
Complete a puzzle with 0 mistakes
Hot Streak
Win 3 days in a row
Week Warrior
Win 7 days in a row
Expert Player
Complete an Expert puzzle
Century Club
Complete 100 puzzles
Brain Power
Complete a puzzle without using hints
Lightning Fast
Complete a puzzle in under 3 minutes
Marathon Runner
Play 10 games in one day
Flawless Streak
Complete 5 perfect games in a row
Dedication
Win 30 days in a row
Sudoku Master
Complete 10 Expert puzzles
Explorer
Play all difficulty levels
Efficiency Expert
Complete a puzzle in under 50 moves
Half Thousand
Complete 500 puzzles
Speed Demon
Average under 5 minutes across 10 games
Comeback King
Win after making 5+ mistakes
Perfectionist
Complete 50 puzzles with 0 mistakes
Legendary
Complete 1000 puzzles