How do I solve a Sudoku?
Choose a Sudoku and size from the menu. You will see an empty Sudoku grid when you visit this puzzle for the first time, or a filled grid from a previous visit.
From here you have a few options:
- Empty the grid with the Reset button.
- Enter numbers or letters by hand. You can switch between numeric and alphanumerical input with the 123/ABC button in the upper right corner. This button is only visible on touch devices.
- Scan a Sudoku. See How do I scan a Sudoku?
- Upload an image of a Sudoku. See How do I upload a Sudoku image?
When the grid is filled you can choose to solve the full Sudoku by pressing the Solve button, or solve a single cell by pressing the Solve Cell button. Most Sudoku are proper Sudoku; this means there is only 1 solution to this puzzle. Sudoku Spoiler also solves non-proper Sudoku up to 10 solutions. To solve a single cell, the Sudoku must be a proper Sudoku.
The Unsolve button removes the solutions and keeps your input.