Sudoku rules illustrated
A completed grid highlights a row, a column and a 3×3 box to show the three standard Sudoku constraints.
X-Wing Sudoku diagram
A candidate diagram shows the four corners of an X-Wing and the sevens it eliminates in the shared columns.
How to read this diagram
In this schematic, rows 2 and 7 each have exactly two candidate sevens: in columns 3 and 8. Those rows must place their sevens in different columns.
Other sevens in columns 3 and 8 can therefore be removed. The diagram deliberately omits other digits and is not a complete playable puzzle.
Image prepared by Sudokumax. Updated .
More to explore
All Sudoku images
Naked pair Sudoku: before and after
A row-level diagram shows two cells containing only 3 and 7, followed by the candidate eliminations they allow.
Killer Sudoku two-cell sum combinations
A complete reference chart of the nonrepeating digit pairs for two-cell Killer Sudoku cages, covering sums 3–17.