Hyper Sudoku · Window Sudoku | 4 Extra 3x3 Regions

✔️ Each row contains digits 1-9 without repetition
✔️ Each column contains digits 1-9 without repetition
✔️ Each standard 3x3 box contains digits 1-9 without repetition
✔️ 4 extra shaded 3x3 regions (top-left, top-right, bottom-left, bottom-right) must also contain digits 1-9 exactly once each.

🎯 The four 3x3 windows (shaded in game board)

①

②

①

②

①

②

③

④

③

④

③

④

✨ The four 3x3 shaded windows (top-left, top-right, bottom-left, bottom-right) each require digits 1–9 once.

🖱️ Click a cell to select it – row, column, box & its hyper window (if any) will highlight.
🔢 Use on-screen numpad or press keyboard 1~9 to enter digits.
🗑️ Press Delete / Backspace or click ⌫ to erase.
⏱️ Timer starts automatically; click "Score" to check accuracy against solution.
↩️ Undo any steps; error count updates in real time (conflicts in rows/cols/boxes/windows).
💡 Tip: Focus on the four extra windows first – they overlap with standard boxes and rows/columns.

🌀 Hyper Sudoku · Window Sudoku