Why does my puzzle have multiple solutions?
A proper Sudoku always has exactly one solution. If the solver finds more than one, it usually means there is an error in the entered numbers — a missing or wrong entry that leaves the puzzle underdetermined.
In this example the puzzle has two solutions. The highlighted numbers in columns 8 and 9 can swap between rows 2 and 9 without breaking any constraint. Use the paging arrows to browse through the solutions.
Some puzzles are intentionally designed with multiple solutions, for example in geocaching puzzles.