How to play Sudoku.
Learn the rules of Sudoku, how to use pencil notes, and how to find your first logical moves. Practice on a free beginner-friendly puzzle.
Put it into practice →One rule, three places to check
Fill the board so that every row, every column and each of the nine 3×3 boxes contains the digits 1 through 9 exactly once. The darker numbers are givens. They are part of the original puzzle and cannot be changed. Each of our puzzles has exactly one solution.
Start with what is already there
Choose an empty cell. Check the digits already present in its row, column and box. Any digit you see in one of those groups is ruled out for that cell. If your row contains 1, 2, 3, 4, 5, 6, 7 and 8, the remaining cell must be 9.
Write possibilities with Notes
Select an empty cell and turn on Notes, or press N on a keyboard. Enter a digit to add a small pencil mark. Enter it again to remove that mark. Turn Notes off before entering a final answer. Automatic notes, available in Settings, calculate candidates from the currently filled digits.
Control the board your way
Tap or click a cell, then choose a number below the board. On a keyboard, use 1–9 for digits, the arrow keys to move, and Backspace or Delete to erase. Undo and Redo reverse board edits. Fixed clues stay in place. Pause covers the board and stops the timer.
Get help without losing the discovery
A Hint begins with an area to inspect. Ask for more to read the reasoning, then reveal the next digit when you want it. If an earlier entry is wrong, the hint points you to a cell to review. Check your notes and the row, column and box around it before continuing.
Choose a first puzzle
The easy collection is solved using singles. Medium introduces locked candidates. Hard adds naked pairs. You can change difficulty above the board. Each daily difficulty has its own saved progress, so switching levels lets you come back to an unfinished puzzle later.