How to play
- Click a cell, then tap a number on the pad or type it on your keyboard.
- Each row, each column and each of the nine 3×3 boxes must contain every digit from 1 to 9 exactly once.
- Turn on Notes to pencil in candidates. Correct entries automatically clear matching notes in the same row, column and box.
Keyboard: 1–9 enter, Backspace erase, arrows move, N toggles notes, Ctrl+Z undoes. Your game is saved in this browser, so you can come back later.
Daily puzzle
Choose Daily puzzle to play the same medium puzzle as everyone else today. It changes at midnight, so it’s a good habit for a morning coffee.
Difficulty levels
Easy puzzles start with about 40 givens and can be solved with singles alone. Medium (about 32) and Hard (about 27) need pairs and box-line reasoning. Expert puzzles start with only 23 numbers.
Solving tips
- Scan for hidden singles. Pick a digit and look for a row, column or box where it fits in only one cell.
- Use naked singles. If a cell has only one possible candidate, place it.
- Pencil in pairs. Two cells in a unit that share the same two candidates remove those digits from the rest of the unit.
- Never guess. Every puzzle here has exactly one solution reachable by logic.
Learn more advanced methods in our Sudoku techniques guide.
FAQ
Do the puzzles have a unique solution?
Yes. Every grid is checked by a solver before you see it.
What does "Show mistakes" do?
When on, digits that don’t match the solution turn red. Turn it off for a classic, unassisted solve.