Start with rows and boxes that already contain the most digits.
A quiet classic
Play Sudoku
online for free.
Play Sudoku online
Difficulty
Choose a square to begin.
Keyboard ready1–9 enter · arrows move · D drafts · Delete erases
Game introduction
What is Sudoku?
Sudoku is a number-placement logic puzzle played on a 9×9 grid. The goal is to complete the grid so every row, column, and 3×3 box contains the digits 1 through 9 exactly once.
You do not need arithmetic to solve Sudoku. Every answer follows from the numbers already on the board, making each puzzle a calm exercise in scanning, elimination, and patient deduction.
- Category
- Numbers
- Difficulty
- Easy–Evil
- Typical game
- 8–15 min
How to play
How to play Sudoku
- Select an empty square, then choose a number from 1 to 9.
- Each row, column, and 3×3 box must contain every number exactly once.
- Use Notes to record several possible digits without committing to an answer.
- Use Check whenever you want a gentle nudge without revealing the answer.
A little help
Sudoku tips
Look for a number that has only one possible home.
When a cell has two candidates, check where those candidates appear elsewhere in its row and column.
Pause after every confirmed digit and rescan the surrounding row, column, and box.
Good to know
Sudoku Frequently asked questions
Is Sudoku free to play online?
Yes. You can play the full Sudoku game free in your browser with no account, subscription or download.
Which Sudoku difficulty should I choose?
Start with Easy if you are learning, choose Medium or Hard for deeper deduction, and try Expert or Evil when you are comfortable tracking several candidates at once.
Can I use pencil marks in this online Sudoku?
Yes. Turn on Notes to place small candidate numbers in a cell, then remove them as the row, column, and box reveal the correct digit.
Can I play Sudoku on a phone or tablet?
Yes. The game is designed for touch screens as well as mouse controls, with keyboard controls included where they suit the puzzle.