Sudoku
About the game and how to play
Sudoku is the world’s best-known number puzzle. Fill the 9×9 grid so that every row, every column and every 3×3 box contains the digits 1 to 9 with no repeats. Every puzzle has exactly one solution. Choose easy, medium, hard or expert, try the diagonal X-Sudoku mode, or play the daily puzzle that is the same for everyone.
- Players
- 1 player
- Category
- Logic puzzles
- Price
- Free, no download, no sign-up
- Where to play
- In the browser on phone, tablet and computer
How to play
- Pick a difficulty or open the daily puzzle.
- Tap an empty cell and enter a digit from 1 to 9.
- Each digit may appear only once in every row, column and 3×3 box.
- Fill the whole grid correctly to solve the puzzle.
Tips
- Pencil in candidates with Notes and keep Auto-remove notes on: placing a digit then clears it from the notes in the same row, column and box, and diagonal in X-Sudoku.
- Hunt for hidden singles first: take one digit and look in each row, column and box for the only cell where it can still go. Easy and Medium puzzles can be finished with singles alone.
- On Hard, look for locked candidates: if a digit's only spots inside a box lie in one row or column, remove it from the rest of that line. Expert puzzles also need pairs.
- In X-Sudoku, start on the diagonals: their cells belong to at least four units instead of three, so digits often fall into place there first.
Frequently asked questions
What is the difference between Easy, Medium, Hard and Expert Sudoku?
Easy starts with roughly 40 given digits and Medium with roughly 30, and both can be solved with singles alone. Hard (about 26 givens) is built to require locked candidates and Expert (about 23) to require pairs as well; every puzzle can be solved by logic without guessing.
When does the daily Sudoku change?
A new daily puzzle, a classic Medium, appears at midnight Azerbaijan time (UTC+4) and is the same grid for everyone. Days you missed stay playable from the archive for up to 60 days back.
Is there a mistake limit?
No, a wrong digit never ends the game; mistakes are only counted. In settings you can turn feedback off, have wrong digits highlighted straight away (Show mistakes), or have them rejected on entry (Auto).
What does the Hint button do?
It first corrects a wrong digit if there is one; otherwise it fills a cell you could have deduced and explains why, such as the only digit that fits that cell. If no such cell exists it reveals one from the solution, and the hints you use are counted in your stats.