Sudoku Online

About this game

Sudoku Puzzle is a free online Sudoku game. No registration, play instantly in your browser. The classic mode offers four difficulty levels: Easy for beginners, Medium for steady practice, Hard for experienced players, and Expert for those who seek a real challenge. Additional game modes expand the standard rules: X-Sudoku adds diagonal constraints, Windoku introduces extra regions on the grid, Killer Sudoku requires groups of cells to meet a target sum, and Kropki adds ratio and difference markers between adjacent cells.

Controls

The goal is to fill a 9×9 grid with digits from 1 to 9 so that each digit appears exactly once in every row, column, and 3×3 box. Some cells are pre-filled — these are your starting clues.