VariantDoku

Palindrome Sudoku: Rules & How to Solve

Each grey line reads the same forwards and backwards, mirroring digits across its centre.

The rule

33

Each palindrome line reads identically in both directions: cells equally spaced from the centre hold the same digit. The middle cell of an odd-length line can be anything legal.

How to solve palindrome sudoku

Pair the mirrors

The first and last cells match, the second and second-to-last match, and so on — solve one, get its twin free.

Mind the line's path

A palindrome that bends through two boxes links cells you'd never otherwise connect.

Length parity

Even-length palindromes have no free centre; odd-length lines leave the middle cell unconstrained by the mirror.

Frequently asked questions

What is a palindrome line in sudoku?
A marked line whose digits read the same forwards and backwards, so symmetric cells are equal.
Do palindrome cells repeat digits?
Mirrored cells share a value, but the usual row, column, and box rules still prevent illegal repeats.
What about the centre cell?
On an odd-length line the centre is its own mirror, so it's free apart from normal rules.

Solve Palindrome Sudoku on your iPhone

VariantDoku has a hand-tested catalog of Palindrome Sudoku and dozens of other variants, with a fresh puzzle every day. No ads, no trackers.

Download on the App Store

Related variants