Rules
Four times the cells, same clean logic.
Each row, column, and outlined 4×4 box uses 1–16 exactly once. There are 256 cells, compared with 81 in a classic grid.
Hexadoku · numbers only
16×16 Sudoku
A larger board without a symbol key. Place numbers 1–16 so every row, column, and 4×4 box contains each number once. The starter has one solution.
- Cells
- 256
- Playable
- 112
- Boxes
- 16
Strategy
Work box by box.
Scan a 4×4 box for missing numbers, then use its four intersecting rows and columns to place them. Repeat before making longer candidate lists.
Keyboard
Use 1–9 and A–G.
Number keys enter 1–9. For fast keyboard entry, A through G map to 10 through 16. Arrow keys move and Delete clears a cell.