Learn how to play Sudoku, improve with practical tips, and watch a featured replay from recent leaderboard records.
How to Play Sudoku
Fill the 9×9 grid so that each row, column, and 3×3 box contains all digits from 1 to 9 without repetition. Start with given clues and deduce the remaining cells logically.
Common Strategies
Single Candidate: When a cell can only be one number, fill it.
Single Position: In a row/column/box, a number can go in only one place.
Candidate Elimination: Use crosshatching to remove candidates using row/column interactions.
Pairs/Triples: Locked candidates help reduce other possibilities in the same unit.
Leaderboard
Browse monthly records. Tip: open a record's replay to learn advanced techniques.