Free Sudoku online
Unlimited puzzles from easy to expert, with notes and explained hints.
Pick a cell, then a number. Use Notes for pencil marks.
Rules & keyboard shortcuts
Fill each row, column and 3×3 box with 1–9, without repeats.
1–9 enter · N notes · ⌫ erase · arrows move.
Learn to play →Progress saved on this device. Take your time.
Fill the grid so every row, column and 3×3 box contains 1–9 exactly once. Pick a difficulty, tap a cell, then a number. Every puzzle here has one unique solution.
Sudoku at a glance
- Grid
- 9×9, divided into nine 3×3 boxes.
- Goal
- Write 1–9 once in every row, column and box.
- Starting digits
- About 22–40 here, depending on difficulty. A unique Sudoku needs at least 17.
- Difficulties
- Easy, Medium, Hard and Expert, rated by the techniques a puzzle needs.
- Daily puzzle
- A new Sudoku every day at midnight in your time zone.
- Tools
- Notes, mistake check, explained hints and a free solver.
- Cost
- Free and unlimited. No sign-up.
Difficulty levels
| Level | Starting digits | Techniques needed |
|---|---|---|
| Easy | about 38–40 | Naked and hidden singles |
| Medium | about 31–32 | Singles, with fewer clues to lean on |
| Hard | about 26–30 | Pointing pairs, box/line reduction, naked pairs |
| Expert | about 22–28 | Repeated eliminations or advanced patterns |
Keyboard shortcuts
Arrow keys move, 1–9 enter a digit, Backspace erases and N toggles notes.
New to Sudoku? Start with how to play Sudoku, then level up with Sudoku tips and techniques. Want something without numbers? Try Cat Sudoku.
Frequently asked questions
How do you play Sudoku?
Fill the 9×9 grid so every row, every column and every 3×3 box contains the digits 1 to 9 exactly once. Some digits are given at the start; you work out the rest by logic.
Is this Sudoku free and unlimited?
Yes. Each time you press New game, a fresh puzzle is created in your browser, checked for a single solution and rated for difficulty. There's no limit and no sign-up.
What's the difference between easy, medium, hard and expert?
Easy and medium puzzles can be solved with singles only (easy just gives more starting digits). Hard puzzles need pointing pairs or naked pairs. Expert puzzles need repeated eliminations or techniques beyond the built-in singles/pairs solver.
How do notes (pencil marks) work?
Turn on Notes, then tap digits to add or remove small candidates in the selected cell. When you place a digit, it's automatically removed from the notes of every cell in the same row, column and box.
Will I lose my game if I close the page?
No. Your current game, time and notes are saved in your browser and restored when you come back.