If you've solved hundreds of sudoku grids and you're looking for something that finally challenges you — this is it. Tsuidoku is not a sudoku variant. It's the next logic puzzle.

🎯 ONE NEW RULE. EVERYTHING CHANGES.
Sudoku has 3 rules: fill rows, columns, and 3×3 boxes with digits 1 to 9. Tsuidoku adds a 4th: every color must also form a complete 1-to-9 sequence across the grid.

Sudoku repeats every digit 9 times. Tsuidoku creates 81 unique number-color pairs. No two cells are ever the same. When you complete a grid, you've built something genuinely unique — not a repetition.

🧠 DEEPER LOGIC. NEW TECHNIQUES.
The 4th combination unlocks reasoning impossible in sudoku. Numbers help place colors. Colors help place numbers. You read the grid two ways at once.

Two exclusive techniques you'll learn:
- Rainbow Technique — use digits to deduce missing colors
- Chromatic Circle — use color sequences to deduce missing digits

All classic sudoku techniques still apply. Adapted to a new dimension.

🎚 6 DIFFICULTY LEVELS
Easy, Medium, Hard, Expert, Master, Diabolic. From your first puzzle to a challenge that breaks experts.

🏆 TWO MODES
- Practice — play at your own pace, no pressure, score saved locally
- Ranked — every game counts toward your ELO rating and your spot on the global leaderboard

🌍 MONTHLY GLOBAL LEADERBOARD
Compete with players worldwide. Track winning streaks, best times per difficulty, personal records, peak rating.

🎓 INTERACTIVE TUTORIAL
Learn the 4th combination and the exclusive techniques in minutes. The rest is the joy of deduction.

🌐 26 LANGUAGES
English, French, Spanish, German, Italian, Portuguese, Japanese, Chinese, Korean, Hindi, Russian, Ukrainian, Polish, Dutch, Swedish, Greek, Thai, Vietnamese, Indonesian, Bengali, Romanian, Czech, Hungarian, Finnish, Danish, Serbian.

✅ PRIVACY-FIRST
Transparent built-in GDPR consent management. You decide what you share, anytime. No dark patterns.

📱 100% FREE
No in-app purchases unlock levels. No paywalls hide features. Every difficulty, every mode, available from day one.

Download Tsuidoku. See what sudoku becomes when you add a 4th dimension.