Tsuidoku: Sudoku Just Evolved

If you've solved hundreds of sudokus and nothing challenges you anymore — this is what's next. Not a variant. A new logic puzzle.

🎯 One extra rule changes everything

Classic sudoku: fill every row, column, and 3×3 box with 1–9. Tsuidoku adds a 4th rule — every color must also run 1 through 9.

The result: 81 unique number-color pairs, no two cells alike. Sudoku repeats each digit 9 times; Tsuidoku never repeats anything. Every grid you finish is one of a kind.

🧠 A new way to think

Numbers help you place colors. Colors help you place numbers. You read the grid two ways at once — reasoning that's simply impossible in sudoku. Every classic technique still works, plus two you'll only learn here.

🏆 Two modes

Practice — no timer, no pressure, your pace.
Ranked — every game feeds your rating and your rank on the global leaderboard.

🌍 Compete worldwide

Winning streaks, best times, personal records, peak rating — track it all against players everywhere.

Add the 4th rule. See what sudoku becomes.