How to Play

Rules

• Fill the grid so every cell contains a digit from 1 to 9.
• Each row must contain the digits 1–9 exactly once.
• Each column must contain the digits 1–9 exactly once.
• Each 3×3 box must contain the digits 1–9 exactly once.
• Every puzzle has exactly one valid solution.

Terminology

• Grid — the full 9×9 board you solve.
• Row — a horizontal line of 9 cells.
• Column — a vertical line of 9 cells.
• Box — one of the nine 3×3 regions.
• Cell — a single square on the grid.
• Candidates — the possible digits a cell could hold, tracked with notes.

Notes

Notes let you mark candidate digits inside a cell without committing a value. Toggle notes mode on with N (or off with M), then press a digit to toggle that candidate. In notes mode, digits never place values — they only edit your candidate marks.

Mistakes and hints on ranked scores

In ranked modes (Levels and Daily) a conflicting placement — a digit that clashes with another in the same row, column, or box — counts as a mistake and lowers your score. Hints reveal a cell and reduce your score by 10% each. Practice mode is never ranked and never affects your score or progress. See the Fair Play page for the full scoring formula.

Keyboard shortcuts

All of the controls below work while playing a puzzle.