4x4 Sudoku is the simplest grid size and a perfect place to learn the core rules. With only four numbers per row and column, you can see patterns quickly and build confidence fast. It is great for younger players or for warming up before larger puzzles.
Practice the basics on the board below and refresh for unlimited new games. Use notes to track possibilities and hints for guidance. Once the rules feel natural, move up to 6x6 or 9x9 Sudoku for longer, more engaging challenges.