What is Jigsaw Sudoku?
Jigsaw Sudoku — also called irregular Sudoku or Nonomino — replaces the nine square boxes with nine irregular regions of nine cells each. Rows and columns work exactly as usual; the twist is that the regions snake across the grid.
Every board on vSudoku uses a freshly generated layout, so no two puzzles look alike, and each has exactly one solution. Hints work here too: they name the technique and highlight the region involved.
Rules
- Each row and column contains the digits 1 to 9 exactly once.
- Each outlined (shaded) region contains the digits 1 to 9 exactly once.
Jigsaw Sudoku strategy
- Regions that bulge into a neighbouring row or column create powerful overlaps — scan where a region crosses only one or two rows.
- Use the rule of 45 across several rows: the cells sticking out of a group of complete regions must balance the cells sticking in.
- Hidden singles are more common than in classic Sudoku, because regions see cells from unusual directions.
- Shaded colours make each region easy to follow — trace a region with your eyes before placing numbers.
New to Sudoku logic? Start with our guide to playing Sudoku and the tips and strategy page — every classic technique works in this variant too.
Frequently asked questions
What is Jigsaw Sudoku?
A Sudoku in which the nine 3×3 boxes are replaced by nine irregular regions. Each row, column and region must contain 1 to 9 once.
Is Jigsaw Sudoku the same as irregular Sudoku?
Yes — Jigsaw, irregular, squiggly and Nonomino Sudoku are names for the same puzzle.
Are the region shapes always the same?
No. Every puzzle on vSudoku gets a newly generated layout of regions, so each board feels fresh.