Need help?
Welcome to the support page for Sudoku World Tournament. Here you can find help, instructions, and contact information.
Common Questions
- How do I change language?
Go to the app menu, tap the flag icon in the top-right, and select your preferred language. - How do I challenge a friend?
Solve a board, tap “Challenge a Friend”, and send the generated code via message or email. - What if I find a bug?
Please contact us using the email below.
🎯 Goal of the Game
Fill in the empty cells so that each row, each column, and each 3×3 area contains the digits 1 through 9 exactly once.
⚡ Difficulty Levels
All boards are generated and tested for solvability based on difficulty, number of clues, and required solving techniques before play begins.
- Easy – many pre-filled numbers, several logical moves available from the start. Perfect for beginners.
- Medium – fewer clues, requires combining basic techniques.
- Hard – minimal clues, advanced solving methods needed (Locked Candidates, Naked Pairs, X-Wing).
- Expert – very few starting numbers, often requires advanced strategies like Swordfish or XY-Wing.
🤝 Challenge a Friend
When you solve a board, tap Challenge a Friend to generate a code. The code can be sent via message or email, and your friend can paste it into the app to play the exact same Sudoku with identical difficulty. The code also includes your result: time, errors, and hints used.
📥 Accept a Challenge
To play a challenge you’ve received, copy the message and paste it into Accept Challenge inside the app.
💡 Tips
- Use Hint if you get stuck – it fills in one correct number.
- Undo/Redo lets you backtrack or repeat moves.
- Pre-filled numbers are always correct and cannot be changed.
- Red numbers are wrong, green borders highlight the same digit across the board.
🌍 Multilingual Support
Sudoku World Tournament is available in 15+ languages including English, Spanish, French, German, Italian, Portuguese (BR), Norwegian, Swedish, Danish, Finnish, Icelandic, Japanese, Korean, Chinese, Thai, and Vietnamese.
**Note**
Sharing to Facebook Messenger groups may not work directly. Copy & paste the challenge code into Messenger instead.