How to Play
Sudoku starts with a partially filled 9x9 grid. Your job is to place the digits 1 through 9 in every empty cell so that each row, each column, and each outlined 3x3 box contains every digit exactly once. A well-constructed puzzle has only one solution.
Use the given numbers as anchors. If a row already has a 5, no other cell in that row can be a 5. The same rule applies to columns and boxes. Work through the grid looking for cells where only one digit is possible.
Controls
Click or tap a cell, then choose a digit. Most versions let you add pencil marks for candidates. On desktop, number keys fill cells quickly.
Scoring
Time and accuracy usually determine your score. Faster solves with fewer mistakes rank higher on the leaderboard.
