Play free Sudoku online with four difficulty levels, pencil marks, hints and undo. Every puzzle has a unique solution and your game is saved on your device.
This tool needs JavaScript to run. Nothing is sent to a server — it works entirely in your browser. The code is open source: view it on GitHub.
Play Sudoku online for free, with no ads and no account. Choose easy, medium, hard or expert, use pencil marks to track candidates, and pick up where you left off — your game is saved on this device.
Fill the 9×9 grid so that every row, every column and every 3×3 box contains the digits 1 to 9 exactly once. Start from the given numbers and use logic — never guessing — to work out the rest.
Easy puzzles start with around 40 given numbers and can be solved with basic scanning. Medium, hard and expert remove more givens (down to about 24), so you will need pencil marks and more advanced techniques.
Turn on Notes (or press N) and tap a number to write it as a small candidate in the selected cell. When you place a final digit, matching notes in the same row, column and box are cleared automatically.
A hint fills in the selected cell with its correct value (or fixes the first wrong cell if there is one). Hints are counted, so you can see how many you used when you finish.
Yes. The puzzle, your entries, notes and the timer are saved in your browser, so closing the tab and coming back later resumes the same game.