Software to Solve & Generate Sudoku Puzzles

Yes — many programs solve and generate Sudoku.

Solvers (Input Puzzle → Get Solution / Hints)

• Web: SudokuWiki.org (Andrew Stuart) — step-by-step logic, strategy names, "Take Step" solver. Sudoku.com, WebSudoku.com — quick solve.
• Mobile Apps: Good Sudoku (Zach Gage) — teaches techniques; Andoku 3 (Android) — powerful solver + generator; Sudoku.com (Easybrain) — hints, daily.
• Desktop: HoDoKu (Java, free/open-source) — advanced solving, puzzle generation, analysis, printing. Sudoku Solver by SudoCue (Windows).
• CLI / Libraries: Python python-sudoku, OR-Tools (CP-SAT), JavaScript sudoku-solver (npm).

Generators (Create Valid Puzzles)

• Most solvers above also generate (difficulty selectable).
• QQWing (C, cross-platform): Fast generator/solver; used in many apps.
• SudokuWiki "Create": Generates symmetric puzzles at chosen grade.
• Custom: Fix givens (e.g., your 2,5,3,7,9 in box 1) → generate completions.

How They Work

• Solving: DLX (Dancing Links / Algorithm X) exact cover — milliseconds for 9×9. Human-style: constraint propagation + backtracking with technique logging.
• Generating: Start with full solution grid → remove clues symmetrically while maintaining unique solution (checked by solver). Difficulty calibrated by hardest technique required.

Beyond Solve/Generate

• Hint systems, technique tutorials, puzzle rating, PDF/print export, variant support (Killer, Jigsaw, Samurai), statistics tracking.

Best free all-in-one: HoDoKu (desktop) or SudokuWiki.org (web).