Jigsaw Sudoku
Same digits, same uniqueness rules — but the nine regions are irregular shapes, not 3×3 boxes.
What makes it Jigsaw
The grid is still 9×9, and every row and column still needs each digit 1–9 exactly once. What changes is the third constraint: instead of nine 3×3 boxes, you get nine irregular regions, each one a connected blob of 9 cells.
It breaks every box-based reflex you've built up. Singles and pairs still apply, but you have to read the region shapes from the grid lines instead of muscle memory. Some jigsaws lean hard on the irregular regions for their early eliminations.
Rules
- Every row contains each digit 1–9 exactly once.
- Every column contains each digit 1–9 exactly once.
- Every irregular region (outlined in the grid) contains each digit 1–9 exactly once.
How Stillgrid plays
- Region boundaries drawn cleanly so you always know which shape you're in.
- Pencil marks, auto-pencil, undo/redo.
- Difficulty graded by the techniques needed against the actual region shapes.
- Free to play. No signup needed to play.
Common questions
What is jigsaw sudoku?
Jigsaw sudoku, also called irregular, squiggly, or nonomino sudoku, replaces the nine 3×3 boxes with nine irregular connected regions of nine cells each. Rows and columns still need the digits 1 to 9, and so does every irregular region.
How is jigsaw sudoku different from classic sudoku?
The grid is still 9×9 and rows and columns are unchanged. The only difference is the third constraint: instead of fixed 3×3 boxes, the regions are arbitrary connected shapes outlined in the grid, which breaks box-based solving habits.
Can I play 6×6 jigsaw sudoku online?
Yes. Stillgrid plays jigsaw sudoku at 6×6 as well as 9×9 — six irregular regions of six cells each, digits 1–6. Few sites offer a playable 6×6 jigsaw online.
Is jigsaw sudoku free on Stillgrid?
Yes. Jigsaw sudoku and every other variant are free to play, with no signup needed to start a puzzle.