Sudoku
Click a square, then type a number or use the pad below. Pencil in notes, undo mistakes, or ask for a hint when you're stuck. Your puzzle is saved if you leave.
Last updated
Keys: arrows move · 1–9 place · 0/Backspace erase · N notes · U undo · H hint
How to play sudoku
- Choose Easy, Medium or Hard, or the Daily puzzle.
- Click a square and type a number from 1 to 9, or use the pad.
- Fill the grid so each row, column and 3×3 box contains 1 to 9 once. Use Notes for pencil marks and Hint if you’re stuck.
About this game
Every puzzle is generated fresh and checked to have exactly one solution before it's shown to you. Fixed clues are shown in a darker colour; your entries are highlighted in red if they conflict with the same row, column, or box. Selecting a square highlights its row, column, box, and every matching number.
Notes mode lets you pencil in candidates; placing a number clears that candidate from the rest of its row, column, and box automatically. A hint fills in the selected square (or a random empty one) and fixes a wrong entry if there is one. Best times per difficulty only count puzzles solved without hints, and they're saved on this device along with any puzzle in progress.
Daily puzzle. Everyone gets the same grid each day: easy on Monday and Tuesday, medium midweek, hard from Friday to Sunday. Solve it to build a daily streak, then share your time (no spoilers, just the result).
Questions about sudoku
What are the rules of sudoku?
Every row, every column and every 3×3 box must contain each number from 1 to 9 exactly once.
How do I start a sudoku?
Look for squares where only one number fits, by checking the row, column and box. Then look for a number that has only one possible place in a row, column or box.
Does every puzzle have one solution?
Yes. Every puzzle is checked to have exactly one solution before you see it.
Is my puzzle saved if I leave?
Yes, on this device, along with your best times. Times only count puzzles solved without hints.