Sudoku
Mouse and keyboard
- Click a square to select it; arrow keys move the selection.
- Type 1–9 to enter a digit; Backspace, Delete or 0 to erase.
- N toggles Notes mode; Z undoes; H asks for a hint.
Touch
- Tap a square, then tap a digit on the keypad under the grid.
- Tap Notes, then tap digits to pencil in candidates. Tap Notes again to go back to entering answers.
- Tap Erase to clear a square, Undo to take a move back, Hint for one deduced square.
This panel
- F full screen
- M sound on or off
- ? this list
- Esc close, or leave full screen
- The clock stops while the board is off screen
Loading Sudoku…
Your record
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No games finished yet. Play Sudoku and your record for each difficulty shows up here.
| Board | Played | Won | Drawn | Win rate | Best | Fastest | Best run |
|---|
Awards for Sudoku
- Clean grid Solve a Hard sudoku with no mistakes and no hints. Needs: hard, clean, no hints Locked
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About Sudoku
Nine rows, nine columns, nine boxes, one answer.
Sudoku needs no arithmetic and no vocabulary, which is why it crossed every border it met. The rules fit in one sentence — each row, column and box holds the digits one to nine once — and everything else is deduction.
The grids here are generated on your device and every one is checked to have exactly one solution before you see it. That single fact is what separates a fair puzzle from a frustrating one: it guarantees that at every step there is a square you can work out, never a square you have to guess. Easy grids fall to singles; medium grids ask you to notice that a digit is pinned to one line inside a box; hard grids want you to pencil in candidates and eliminate pairs. Notes, undo and a hint that explains its reasoning are all here, and the clock does not start until you make your first entry.
Also searched for as
- sudoku online
- soduku
- sudoko
- number puzzle
- su doku
Whichever name you know it by, it is the same game: it runs in this browser, with no download and no sign-up.
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How to play Sudoku
- Fill the empty squares so that every row, every column and every 3×3 box contains the digits 1 to 9 exactly once.
- Tap a square, then tap a digit on the keypad or press it on the keyboard. The printed digits are the givens and cannot be changed.
- Turn on Notes to pencil small candidate digits into a square while you work out which one it is. Tap the same digit again to remove it.
- A digit that clashes with the same digit in its row, column or box is marked at once. Erase it or undo — the puzzle has exactly one solution, so a clash always means a mistake.
- Hint fills nothing for you. It points at one square, tells you which digit goes there and why — the only place a digit can go in its box, or the only digit that fits the square.
- The grid is solved when every square is filled with no clashes. The clock starts on your first entry, not when the page loads.
Strategy that actually helps
- Scan one digit at a time. Pick a digit that already appears five or six times, and for each box where it is missing ask which squares in that box are not already ruled out by that digit's row and column. Very often only one is left.
- Look for the square with the fewest candidates, not the digit with the fewest homes. A square that can only hold one digit is a naked single, and it is the most common move in every grid.
- On medium and hard grids, pencil notes before you guess. When two squares in a row share the same two candidates and nothing else, those two digits belong to those two squares — and can be crossed off everywhere else in the row.
- Check a box that is missing two or three digits before anything clever: with so few gaps, the rows and columns running through it usually settle at least one.
- Never guess. Every grid here has exactly one solution, which means every square is deducible without trial and error; if you are stuck, the hint shows the deduction rather than the answer.
Controls
Mouse and keyboard
- Click a square to select it; arrow keys move the selection.
- Type 1–9 to enter a digit; Backspace, Delete or 0 to erase.
- N toggles Notes mode; Z undoes; H asks for a hint.
Touch
- Tap a square, then tap a digit on the keypad under the grid.
- Tap Notes, then tap digits to pencil in candidates. Tap Notes again to go back to entering answers.
- Tap Erase to clear a square, Undo to take a move back, Hint for one deduced square.