Classic Sudoku online
Play classic Sudoku online with daily puzzles, Ghost Race, multiplayer and free practice. Learn the rules and practise logical solving techniques.
Choose easy, medium, hard or expert in the game selection. You decide when to start.
How the rules work
Each row, column and 3 × 3 box must contain the digits 1–9 exactly once. Start by finding the missing digit in the almost-complete row.
Worked example
A row contains 1, 2, 3, 4, 5, 6, 7 and 8. The missing digit is 9. Also check that the placement fits its column and box.
How can I get help?
In free practice you can show candidates and request gradual hints. On mobile, open the guide from the input dock. Lessons explain a technique through smaller exercises before you use it on a full puzzle.
Choose how to play
Daily puzzles
Each day offers four difficulties per variant. Play the daily challenges, build a streak and compare times on the leaderboard. You can begin as a guest; an account lets you save your results.
Ghost Race
Race a recording of a player’s first attempt on a puzzle you have not played, when one is available, or race the computer. Choose a difficulty and ghost tempo. Watch the opponent’s progress while solving your own board.
Multiplayer with friends
Choose a variant and difficulty, create a room and share its room link. Race on individual boards, solve together in Co-op or play team against team. Automatic matchmaking finds players with the same variant and difficulty, for both classic Sudoku and Killer.
Free practice with hints
Practise without ranking or a race clock. The guide first reveals a technique, then its supporting cells and finally the full reasoning. Show candidates or let the guide apply a step. Practice boards are not saved when you leave the page.