Play a free daily sudoku online, unlimited puzzles, multiple difficulty levels, no sign-up needed. Fill the 9x9 grid so every row, column, and 3x3 box contains the digits 1 through 9. Start with easy puzzles to learn the logic, then work up to hard and expert grids as your skills improve. One of the best brain games you can play every day, and this version is always free and ready to go.