Palindrome Sudoku
The digit sequence along a line reads the same forwards and backwards
Palindrome Sudoku is fully playable. Choose a difficulty and start solving.
Palindrome Sudoku marks lines on the grid whose digit sequence must be a palindrome — reading the same in both directions. If a line has cells A-B-C-D-E, then A=E and B=D, while C is the central digit. This creates pairs of cells that must share the same value, acting as powerful equality constraints across the grid.
Like all Sudoku variants, Palindrome Sudoku builds on the classic 9×9 foundation. Every row, column, and 3×3 box must contain each digit from 1 to 9 exactly once. The variant constraint is added on top of these standard rules, never replacing them.
If you're new to Sudoku, start by learning the basic rules and techniques before attempting variants.
Techniques Useful for This Variant
| Technique | How it applies |
|---|---|
| Pencil Marks / Notes | Essential for tracking candidates alongside the variant constraint |
| Obvious Singles | Cells narrowed to one candidate by the combined constraints |
| Hidden Singles | Digits with only one valid cell in a unit after variant elimination |
| Pairs and Triples | Locked candidates exposed by the additional constraint |