How to play Sudoku

Sudoku is a puzzle of nine rows, nine columns and nine 3 × 3 boxes. Some numbers are already in place. Fill in the rest so that every row, every column and every box has the numbers 1 to 9, each exactly once. No arithmetic is needed: the numbers are only symbols, and the puzzle is pure logic.

Placing numbers

• Tap a square, then tap a number below the board. On a computer you can also type the number.
• The row, column and box of the square you picked are shaded, and every copy of the same number lights up.
• Dark numbers came with the puzzle and cannot change. Your numbers are blue.
• Tap Notes to write small pencil marks of the numbers that might fit. When you place a number, it is wiped from the notes around it.
• Erase clears a square, and Undo takes back as many moves as you like.

Easy, Medium and Hard

Every puzzle here has exactly one answer and can be solved by reasoning alone, without guessing. Easy starts with at least 38 numbers on the board. Medium gives fewer numbers but still needs only the simple "one number fits" reasoning. Hard needs a trick or two more, such as a number that is locked into one row of a box. Pick the level in Settings.

Mistakes, hints and the clock

A number that does not belong turns red. Each mistake adds 10 seconds to your time, so guessing does not pay. Stuck? Hint fills in the next number you can work out and tells you why, for 30 extra seconds. The clock only runs while the puzzle is on your screen.

Tips that solve puzzles faster

1. Start with the most common number. If six 7s are already placed, the last three are easy to find.
2. Work box by box. Look at the rows and columns that cross a box: each number already in them crosses out squares.
3. Look for the last empty square. A row, column or box with eight numbers tells you the ninth.
4. Count what is missing. If a square sees eight different numbers in its row, column and box, the ninth is the answer.
5. Pencil in pairs. When two squares in a box can only be 3 or 8, those two numbers are spoken for.
6. Never guess. If you are not sure, write notes and look somewhere else for a while.

Today's puzzle

Every day there is one Daily Puzzle, Medium level, the same for every player. Solve it as fast as you can and see how you compare with everyone else who played today. Your first finish of the day is the one that counts.

Questions

Stuck on the puzzle in the newspaper? Type it into the sudoku solver. It checks that it was copied right and shows the next number with the reason.

Do I need to be good at math? No. Sudoku uses numbers only as nine different symbols. There is no adding anywhere.

Can a puzzle have two answers? Not here. Every puzzle is checked to have exactly one answer before you see it.

Can I play with a keyboard? Yes. Use the arrow keys to move, the number keys to fill in, N for notes and Backspace to erase.

Do I need an account? No. Your puzzles, streak and settings stay in this browser. A free account keeps them on every device.