Free Jigsaw Sudoku Solver

Jigsaw Sudoku Solver: Solve Irregular Sudoku Online

Our free Jigsaw Sudoku Solver helps you solve irregular Sudoku puzzles where the familiar 3x3 boxes are replaced by nine jigsaw-shaped regions. Draw each region exactly as it appears in your puzzle, add any given digits, and the solver will complete the grid using row, column, and custom-region constraints.

Jigsaw Sudoku is also known as Irregular Sudoku or Nonomino Sudoku. The goal is still to place the digits 1 to 9 in every row and every column, but the box rule changes: each colored or outlined jigsaw region must also contain the digits 1 to 9 exactly once. Because those regions can snake through the grid, a normal Sudoku solver cannot reliably solve these puzzles unless it understands the custom shapes.

How to Use the Jigsaw Sudoku Solver

1. Choose Regions mode and drag across exactly 9 connected cells to create each jigsaw box.
2. Repeat until all nine regions are defined. Click a saved region if you need to review or delete it.
3. Switch to Numbers mode, then enter the printed givens from your puzzle.
4. Click Solve to complete the grid and check whether the puzzle has a unique solution.

Why Region Drawing Matters

The hardest part of entering an irregular Sudoku is describing the box layout. A text code for nine custom regions is easy to mistype, especially when shapes bend around each other. The drag editor lets you trace the puzzle visually: each region becomes a colored 9-cell area with thicker borders, so you can compare it against the source puzzle before solving.

What the Solver Checks

• Every row contains no repeated digit.
• Every column contains no repeated digit.
• Every jigsaw region contains exactly 9 cells and no repeated digit.
• All 81 cells belong to one and only one region.
• The completed puzzle has one solution or multiple possible solutions.

This Jigsaw Sudoku solver runs locally in your browser. Your givens, region layout, and exported JSON are not uploaded anywhere.