Sudoku API
Generate, solve and validate Sudoku puzzles through a fast, fully-local API. Create fresh puzzles at four difficulty levels (easy, medium, hard, expert), each guaranteed to have exactly one solution, returned as both an 81-character string and a 9x9 grid alongside the full solution. Solve any valid puzzle with a backtracking engine that also reports whether the solution is unique, and validate a grid to detect rule conflicts and completeness. Inputs accept an 81-character string (0 or . for blanks) or a 9x9 array, by GET or JSON POST. Pure server-side compute with no third-party upstream, so responses are instant and the service is always available. Ideal for puzzle apps and games, newspapers and printables, tutors and training-data generation.
api.oanor.com/sudoku-api
