How to play Sudoku

Your goal

Fill every empty tile so each row, column, and outlined box contains every symbol exactly once. Starting clues stay fixed. For a classic 9 × 9 puzzle, use the numbers 1 through 9.

Rows run across the board; columns run down it. Boxes are the smaller outlined rectangles. A number must fit all three places at once: its row, its column, and its box.

Changing to shapes, garden emoji, or fruit in Settings changes the appearance, not the rules. Each symbol still belongs exactly once in each row, column, and box.

Find your first move

Start with a row, column, or box that is almost full. Work out its missing symbols, then check where each can go without repeating a symbol in a crossing row or column.

For example, a 4 × 4 row containing 1, 2, an empty tile, and 4 is missing 3. The empty tile must be 3. Check its column and box too: a conflict can reveal a mistake in an earlier entry.

Two useful patterns are:

• One possibility in a tile: its row, column, and box rule out every symbol except one.
• One place for a symbol: within a row, column, or box, only one empty tile can hold a particular symbol.

Enter symbols and notes

Select an empty tile, then choose a symbol from the keypad or type its number. Use Erase to clear an entry. Undo reverses a move.

Turn on Enable Notes in Settings to add the Write / Notes selector. In Notes mode, symbols become small pencil marks showing possibilities. Select a note again to remove it. Notes are reminders, not checked answers.

Automatic notes displays possible symbols from the current board. Your manual notes remain separate and return when you turn automatic notes off. Clear matching notes removes matching pencil marks from related tiles after an entry. Valid symbols only limits the keypad to symbols that fit the current row, column, and box; it does not guarantee the solution.

Use a hint

Hint explains a deduction and highlights its target. Expand the explanation for more detail; when several steps are needed, use the previous and next controls to follow them. Temporary candidate markings illustrate the explanation without changing your notes.

Try entering the answer yourself, or choose Show me to apply the hint as an assisted move. Undo can reverse that move. Incorrect entries may need to be cleared before the next deduction can be explained.

Choose a puzzle

Open the game menu and choose New puzzle. Choose Daily, or continue through numbered 9 × 9 levels in Beginner, Advanced, Expert, or Pro. Each category starts gently and gradually offers a wider range of puzzles within its difficulty. Buttons show completed levels and whether a puzzle is in progress.

Daily is a 9 × 9 puzzle for your local calendar date. Everyone gets the same puzzle for that date. Monday and Tuesday are approachable, and difficulty builds toward upper Expert on Sunday. Daily puzzles show their date; numbered levels have separate sequences for each category.

Each category keeps its own puzzle, notes, undo history, and timer. Switch categories whenever you like, and sign in to sync them across devices. A new Daily becomes available at local midnight and leaves the open puzzle alone. Starting a newer Daily asks before replacing an unfinished daily puzzle.

Controls

Open How to play Sudoku in the game menu and choose Learn by playing for a guided 4 × 4 introduction. Settings also offers symbol styles, conflict and peer highlighting, and an optional timer.