Sudoku Online Free9️⃣Sudoku
Fill the grid with logic.
About Sudoku
Every row, column and 3x3 box must contain the digits 1 to 9. Fresh puzzles are generated every time on four difficulties, with pencil marks, hints and mistake checking.
Controls
- ▸Click a cell then type a digit
- ▸Delete / 0 clears
- ▸N toggles pencil mode
- ▸P or Esc to pause
- Difficulty
- ★★★★★
- Session
- ~10 min
- Plays
- 0
- Time played
- 0 min
How to play Sudoku
Sudoku is a 9x9 grid split into nine 3x3 boxes, with some cells already filled. Fill the rest so every row, column and box contains the digits 1 to 9 exactly once. Each puzzle is freshly generated with exactly one solution. Choose Easy, Medium, Hard or Expert; harder levels start with fewer numbers.
Click a cell and type a digit or tap the number pad. 0, Delete or Backspace clears it, and the arrow keys move around. Press N or Pencil to add small candidate notes. With Mistakes on, wrong digits turn red. Hint fills in a correct digit but adds 30 seconds, and Undo (U or Ctrl+Z) steps back. Your time is your score, so faster is better.
Tips
- ▸Scan one digit at a time: for each box, see where that digit can't go because of its row or column. Often only one cell is left.
- ▸Use pencil marks to spot cells with a single candidate. Placing a digit clears it from the notes in its row, column and box.
- ▸The small numbers on the pad show how many of each digit are left, so a digit with one left is a quick win.
Sudoku FAQ
- Does every puzzle have only one solution?
- Yes. Each puzzle is checked when it is generated to make sure it has exactly one correct solution.
- Is there a penalty for mistakes or hints?
- Mistakes never end the game; with Mistakes on they just show in red. Each hint adds 30 seconds to your time.
- Which Sudoku difficulty should I choose?
- Easy starts with about 38 numbers and Expert with as few as 23. Begin on Easy or Medium and move up once you can finish without hints.
