Solve and explain
Enter a grid or paste a puzzle, solve and explain it, or start a private browser-local play session.
Given Solver-filled
Validation, solving, classifications, and metrics are calculated on the server.
Start with the visible grid. Its current digits become immutable clues.
Load a valid puzzle, then choose Start Play.
Player notes are private aids and are never used as solver candidates.
Generation proves uniqueness on the server. A category may stop safely if no honest match is found within its limit.
Enter a puzzle in the grid or paste one below.