sudokly
9×9 · Medium to evil

Jigsaw Sudoku

Sudoku with non-rectangular regions. same digit constraint, weirder shapes.

Jigsaw·00:00
About jigsaw

What jigsaw sudoku feels like.

Jigsaw sudoku. also called squiggly or geometric sudoku. keeps the row and column rules of classic sudoku but replaces the nine 3×3 boxes with nine irregular regions of nine cells each. The same digit constraint applies, but the geometry forces you to think spatially.

Rules

  1. Each row contains digits 1–9 exactly once.
  2. Each column contains digits 1–9 exactly once.
  3. Each irregular region of nine cells contains digits 1–9 exactly once.
Key rule
Irregular regions replace 3×3 boxes
Difficulty range
Medium to evil
Tips
  • Long, snake-like regions create unusual elimination paths. scan them carefully.
  • Pointing pairs and box-line reduction take on new forms; the 'box' is now whatever shape the region happens to be.
  • Pencil marks are essential.

Jigsaw Sudoku FAQ

What's the difference between jigsaw and classic sudoku?

Only the box shape. In classic sudoku, the nine boxes are 3×3 squares. In jigsaw, they're irregular polyominoes of nine cells each.

Are jigsaw regions always nine cells?

Yes. Every region in a 9×9 jigsaw sudoku has exactly nine cells; otherwise the digit constraint can't be satisfied.

Is jigsaw sudoku harder than classic?

Generally yes, because spatial intuition about boxes has to be rebuilt from the region shapes.

Can I use the same techniques as classic sudoku?

Most of them, yes. they just look different. X-wing and swordfish work identically; box-line reduction generalises to region-line reduction.

Are jigsaw puzzles unique?

Yes. Uniqueness is verified during generation.