Sudoku is a number puzzle where you fill a 9 by 9 grid so every row, column and 3 by 3 box holds the digits 1 to 9 once. This free version runs in your browser with no download or sign up, works on phones and computers, and keeps working offline after the first load. Every puzzle is made fresh and has exactly one solution.
Inspired by: The classic Sudoku number puzzle, popular in newspapers since the 1980s.
How to play Sudoku
- Pick Easy, Medium or Hard. Harder puzzles start with fewer given numbers.
- Tap a square, then tap a number below the grid to place it.
- Each row, column and 3 by 3 box must contain 1 to 9 with no repeats.
- Switch on Notes to jot small pencil marks when you are not sure yet.
- A wrong number counts as a mistake. Three mistakes end the round, so think before you tap.
- Fill the whole grid to win. Faster and cleaner solves earn more points.
Controls
- Keyboard: Arrow keys move the highlight. Number keys 1 to 9 write a digit. N toggles notes, Backspace erases, U undoes, H gives a hint.
- Mouse: Click a square, then click a number on the pad.
- Touch screen: Tap a square, then tap a number. Use the Notes, Erase, Undo and Hint buttons under the grid.
Tips to score higher
- Start with the numbers that already appear many times on the grid. They are the easiest to place.
- Look for a box, row or column that is nearly full. Only one digit can finish it.
- Use Notes on harder puzzles. When a square has only one note left, that is your answer.
- Tap a filled square to highlight every matching digit. It makes gaps easy to spot.
- Save your hints for the moments when you are truly stuck.
The story behind Sudoku
Number grids like Sudoku grew from Latin squares studied by the Swiss mathematician Leonhard Euler in the 1700s. The modern puzzle first appeared in a US magazine in 1979 under the name Number Place. A Japanese publisher called it Sudoku in the 1980s, and it spread worldwide after 2004 when newspapers in the UK began printing it every day. Many Indian families know it from the corner of the morning paper, solved with a pencil and a cup of chai. This version brings that quiet, satisfying moment to your screen whenever you have a few minutes.
Questions players ask
Is this Sudoku game free?
Yes. It is free to play, with no sign up, no download and no ads inside the game.
Does every puzzle have only one solution?
Yes. Each puzzle is checked by the game so there is exactly one correct answer and you never need to guess.
What do the Notes do?
Notes let you write small candidate numbers in a square. They are saved while you play and clear themselves when you place a correct digit nearby.
Can I play Sudoku offline?
Yes. Open the page once with internet. After that it loads and plays without a connection.
How is my score worked out?
You earn points for finishing, with a bonus for speed. Mistakes and hints take a few points away.