Sudoku

Sudoku is a logic puzzle on a nine-by-nine grid. Fill every empty cell with a digit from 1 to 9 so that each row, each column and each of the nine three-by-three boxes contains every digit exactly once. Every puzzle here has exactly one solution, so it can always be solved by reasoning — no guessing needed.

1. Choose Daily for today’s shared puzzle, or Random for a new one, and pick a difficulty.
2. Select a cell by tapping it or moving with the arrow keys.
3. Enter a digit with the number pad or your keyboard. Clashing digits turn red.
4. Switch Notes on to pencil in candidates; placing a digit clears that note from its row, column and box.
5. Fill the grid correctly to stop the clock. Your best time is saved on this device.

• Difficulty is set by how many clues remain (40, 32 or about 26). A puzzle with fewer clues is usually, but not always, harder.
• The daily puzzle changes at midnight in your time zone.
• Only the daily puzzle’s progress is kept if you reload; a random puzzle starts fresh.
• Puzzles are generated in your browser and the game works offline. Today’s progress and your best time are stored only on this device and can be deleted from the You page.

Look for a digit that can only go in one place within a row, column or box. Pencil notes help you spot cells with a single remaining candidate.

Yes. It is generated from the date and difficulty, so everyone playing on the same day gets the same grid — without any server.

It highlights digits that repeat in a row, column or box. It doesn’t reveal whether a non-clashing digit is wrong, so the puzzle stays a puzzle.

Yes. Tap a cell, then use the on-screen number pad, Notes and Erase buttons.