Sudoku:Infinite Puzzles

4 difficulties,800 puzzles were provided.
But you can generate the puzzles as many as you like by the Special Puzzle Generator. So you actually have the infinite puzzles.
And any puzzle that stumped you can be solved in half a second by The Advanced Quick Solver.
Sudoku introduction:
Sudoku is a world wide famous puzzle game, the game logic is simple, but the numbers arrangement changes endless. The objective is to fill a 9×9 grid with numbers so that each column, each row, and each of the nine 3×3 sub-grids contains all of the numbers from 1 to 9.