Sudoku online

Fill the grid so every row, column and 3×3 box holds the digits 1 to 9 once. Each difficulty has one daily puzzle, the same for everyone, so you can race other players on today's leaderboard. Every puzzle has exactly one solution.

Loading today's leaderboard…

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Today's puzzle

Show mistakes

How to play Sudoku

Pick a difficulty. Today loads the daily puzzle for that level; New puzzle gives you a fresh practice grid as often as you like.
Tap a square, then tap a number (or type 1–9 on a keyboard). Use the arrow keys to move around the grid.
Not sure yet? Turn on Notes and tap numbers to pencil in candidates. Placing a number clears it from the notes in the same row, column and box.
Wrong numbers turn red while Show mistakes is on. Turn it off for a real challenge. Undo steps back one move (Ctrl+Z or ⌘Z works too).
The clock starts with your first move and stops when the grid is complete. Finish a daily puzzle and you can add your time to the leaderboard under a nickname.

How the difficulty levels work

Every puzzle is generated in your browser from a seed (the date and level for the daily puzzles), then checked by a solver: a square is only emptied if the puzzle still has exactly one solution. The levels differ in how the remaining puzzle can be solved:

Easy (about 38 givens) and Medium (about 31): solvable with singles alone, the square where only one number fits, or the number that fits in only one square of a row, column or box.
Hard (about 27 givens) and Expert (as few as 22): singles are not enough. You will need notes and techniques such as pairs, pointing candidates or X-wings.

Because the daily puzzle comes from the date, everyone playing the same level today gets the same grid, so the times on the leaderboard are comparable.

Sudoku tips

Scan each number in turn: look for the box where a 1 can only go in one square, then 2, and so on.
Fill the most crowded rows, columns and boxes first; they have the fewest options left.
On Hard and Expert, note every candidate in a box before you guess. Two squares in a unit that share the same two candidates rule those numbers out everywhere else in that unit.

Frequently asked questions

Is this Sudoku free and unlimited?

Yes. There is one daily puzzle per level, and New puzzle makes a fresh grid whenever you want. No account or download is needed.

Does every puzzle have exactly one solution?

Yes. Squares are only removed while a solver confirms that the grid still has a single solution, so you never need to guess between two endings.

Why is my practice time not on the leaderboard?

Only the daily puzzles are ranked, because everyone plays the same grid. Practice puzzles are different for every player, so their times are not comparable.

Is my progress saved?

Your daily puzzle is saved in this browser while you play, so you can close the tab and come back to it later today. Practice puzzles are not saved.

What name should I use on the leaderboard?

Any nickname of 2 to 20 characters. Names and times are public, so please don't use your full real name. See the privacy policy.