A Sudoku solver is a tool or program designed to help users find solutions to Sudoku puzzles. These solvers can be found in various forms, including online applications, mobile apps, and software. They use algorithms to analyze the puzzle's grid and determine the correct placement of numbers, ensuring that each row, column, and region contains the digits 1 through 9 without repetition. Many Sudoku solvers offer features like step-by-step guidance, hints, and the ability to solve puzzles of varying difficulty levels. Some solvers can even generate new puzzles for users to solve, making them a valuable resource for both beginners and experienced players looking to improve their skills.