Rules

Sudoku Basics

Sudoku is a logic puzzle played on a grid. Your goal is to fill in the empty cells so that each row and column contains each number exactly once.

Hard Mode (9×9)

Use digits 1–9. Each 3×3 subgrid must also contain the digits 1–9 exactly once.

Easy Mode (6×6)

Use digits 1–6. Each subgrid (2×3) must contain the digits 1–6 exactly once.

Tips

• Start with rows/columns that have the most fixed numbers.
• Eliminate candidates using row/column/subgrid constraints.
• Work slowly and verify each placement.