Sudoku – Free Online Logic Puzzle
Sudoku
- ◈ Puzzle
- Desktop + Mobile
Free · No sign-up · Desktop & mobile
Sudoku is a classic logic puzzle with a fresh grid every game. Fill the cells so each row, column, and 3x3 box contains the digits 1 to 9 only once. It is calm, focused play that still gives your brain a clear task. With three difficulty levels and a unique solution for each puzzle, it is easy to start and satisfying to finish.
How to play
Choose a cell and enter a digit from 1 to 9. Keep checking the row, column, and 3x3 box around that cell so no number repeats. If you are not sure, add pencil notes first and narrow the options as you go. Use the hint button when you want help with one correct cell, or erase a digit if you need to change your answer. The game offers three difficulty levels, so you can pick a pace that suits you.
Controls
- Desktop: Click a cell, then type 1-9. Use N for notes, H for hint, and the arrow keys to move.
- Mobile: Tap a cell, then tap a digit on the side pad. Use the on-screen buttons for notes, hint, and erase.
Features
- Fresh puzzle every game
- Unique solution for each puzzle
- Three difficulty levels
- Pencil notes for planning
- Hint and erase tools
Tips & strategy
- Start with cells that have only one possible digit.
- Use notes when more than one number could fit.
- Scan one digit at a time across the whole grid.
- Work on rows, columns, and boxes together, not separately.
Progression
A good Sudoku session usually starts with the easiest openings: cells that already have only one clear value. From there, move through the grid slowly and keep your focus on one digit at a time. That makes repeated numbers easier to spot. Pencil notes help most when the puzzle becomes crowded. Add them early instead of guessing, then remove possibilities as new numbers appear. If you get stuck, switch to another row, column, or box rather than forcing a move. The hint can help, but using it sparingly keeps the puzzle more rewarding. With three difficulty levels, you can choose a quicker round or a longer, more careful solve.
About this game
Sudoku is a carlogames game that runs in your browser on desktop and mobile. Your personal best is stored on your device only, and no personal data is collected.
FAQ
How does Sudoku stay unique every time I start a new puzzle?
Sudoku gives you a fresh grid every game, and each puzzle has one unique solution. That means you are always solving a new logic puzzle, not repeating the same board. The challenge is to fill every row, column, and 3x3 box correctly.
What is the best way to use pencil notes in Sudoku when I am unsure?
Pencil notes are useful when more than one digit could fit. Add them first instead of guessing, then narrow the options as other cells are solved. This helps you keep track of possibilities and makes crowded parts of the grid easier to manage.
How does the Sudoku hint button work if I get stuck on one cell?
The hint button gives help with one correct cell when you want a nudge. If you still need to change your answer, you can erase a digit and try again. It is a simple way to keep moving without breaking the puzzle.
What should I focus on first in Sudoku to solve a puzzle faster?
A good start is to look for cells that already have only one possible digit. Then scan one digit at a time across the whole grid and check rows, columns, and 3x3 boxes together. This makes repeated numbers easier to spot.
How do the three difficulty levels in Sudoku change the way I play?
Sudoku offers three difficulty levels, so you can choose a pace that suits you. That makes it easy to start and satisfying to finish, whether you want a quicker round or a more careful, longer solve.