A little space to think.
Sudoku, without the distractions. Choose a difficulty or settle into today's puzzle.
Generating a unique-solution puzzle…
Preparing your board
Finding a puzzle with exactly one solution.
How to play Sudoku
Fill every row, column and 3×3 box with the digits 1–9, each used once. The darker starting numbers are fixed. Select an empty cell to see its row, column and box highlighted. Matching digits are highlighted too.
Use pencil notes to remember possible numbers. Fill notes calculates candidates from the current entries; a mistaken entry can affect those candidates. Check highlights entries that disagree with the solution. Undo restores the last change, including notes. Hints and checks remain counted after undo. There is no time limit.
Every generated puzzle is checked for exactly one solution. Easy starts with more clues; Hard has fewer. The daily puzzle is the same for a given date on your device. It uses Medium difficulty. Progress and your last 20 completed puzzles are stored in this browser when storage is available. Switching away pauses the timer; clearing browser data removes saved progress.