Play Jigsaw Sudoku Online — Free

Jigsaw Sudoku (also called Irregular Sudoku or Squiggly Sudoku) replaces the standard nine 3×3 boxes with nine irregular, jigsaw-shaped regions. Every row, column, and jigsaw region must still contain the digits 1–9 exactly once — but the irregular shapes create a completely different solving experience.

Because the regions don’t align neatly with rows and columns, standard box-based Sudoku techniques become less predictable. Candidates that would be eliminated by a box constraint in regular Sudoku may survive in a jigsaw puzzle because the irregular region crosses rows and columns in unexpected ways.

Jigsaw Sudoku is a fresh challenge for experienced Sudoku solvers who feel they’ve mastered the standard puzzle. The same fundamental logic applies, but the unfamiliar region shapes force you to think about constraints more carefully rather than relying on pattern recognition.

When a jigsaw region’s cells in a particular row or column are limited to just one or two positions, those cells act as powerful constraints — treat them exactly as you would a standard box in classic Sudoku.