Play Sudoku
Select a difficulty. The slider matches the original java applet: more givens is simpler; fewer givens is harder.
Play Sudoku Online
The puzzle is a 9×9 grid divided into 3×3 regions. Fill each blank square with a number from 1 to 9 so each row, column, and region contains every number once.
Click a square to select it. A selected blank square shows a pencil-mark grid; tap a small number to toggle a pencil mark, or use the number buttons below the board to enter your answer — you can also toggle between "answer mode" and "hint mode" by using the 🖊️ and ✏️ buttons to the left and right of the number row (switching to ✏️ means that a click/tap of a number will now fill in [or remove] the hint instead of filling in the answer).
Keyboard entry, Delete/Backspace, and arrow-key movement are supported.
Helpful controls include Mark hints, Auto-unmark to remove pencil marks (automatically) after correct answers, Mistake alert, restart, undo, and sound control. There is a five-mistake limit per game.