Sudoku 4 in 1

Sudoku is a popular logic-based puzzle game that can be played online. The game Sudoku 4 in 1 consists of a 9x9 grid, divided into nine 3x3 sub-grids. The objective of the game is to fill each of the 81 cells in the grid with a number from 1 to 9, with each number appearing only once in each row, column, and sub-grid.