Fill every empty cell with a number so that each row, each column, and each box (thick-bordered group) contains every number exactly once — no repeats.
🔢 Grid Sizes by Level
Level 1: 3×3 grid — numbers 1–3
Levels 2–3: 4×4 grid — numbers 1–4 (2×2 boxes)
Levels 4–6: 6×6 grid — numbers 1–6 (2×3 boxes)
Levels 7–9: 9×9 grid — numbers 1–9 (3×3 boxes)
🎮 Controls
Tap a cell to select it, then tap a number to fill it
✏️ pencil button — toggle note mode for possible numbers
⌫ eraser — clear a cell
↩ undo — reverse your last move
You get 3 mistakes maximum — be careful!
💡 Tips
Start with rows, columns, or boxes that are almost full
Use pencil marks to track possible numbers
If only one number can fit — that's the answer!
Smaller grids are great for learning before 9×9
🏆 Hall of Fame
Complete a puzzle to save your time! Top 50 fastest per level are recorded.