Samurai Sudoku Solver

Enter a five-grid Samurai Sudoku puzzle, solve all 369 active cells, step through the answer, or import a compact puzzle string.

Samurai Sudoku Solver: solve five overlapping Sudoku grids online

This free Samurai Sudoku Solver is built for the full Gattai-5 layout: four corner Sudoku grids plus one central grid, overlapping in four shared 3x3 boxes. A complete Samurai Sudoku has 369 active cells, and every one of the five 9x9 grids must obey standard Sudoku rules.

Click cells and enter the givens from your puzzle, then solve the whole Samurai grid, reveal one step at a time, or export the puzzle string. The overlapping boxes are handled automatically, so a clue entered in a shared region constrains both connected grids.

How to use the Samurai Sudoku solver

  1. Enter the givens into the five-grid layout.
  2. Use the highlighted rows, columns, and boxes to check shared constraints.
  3. Press Solve to complete the puzzle, or Step to reveal one cell.
  4. Import 369 active cells, or 441 full-board cells if your source includes inactive spaces.
  5. Read the solution message to see whether the puzzle is unique.

Samurai Sudoku rules

Each of the five 9x9 Sudoku grids must contain digits 1-9 once in every row, column, and 3x3 box. The four corner grids overlap the central grid in a 3x3 box, so those nine cells belong to two grids at the same time.

Why use a dedicated Samurai Sudoku solver?

A normal Sudoku solver only understands one 9x9 grid. A Samurai Sudoku solver must preserve five separate row, column, and box systems while keeping the four overlaps synchronized. This page is designed for that exact structure, including import/export, contradiction checks, step solving, and uniqueness testing.

Samurai Sudoku Solver FAQ

How many cells are in Samurai Sudoku?

The full 21x21 board has 441 positions, but only 369 are active puzzle cells.

Can I paste a puzzle string?

Yes. Paste 369 active cells read left to right, top to bottom, or 441 full-board cells where inactive positions can be 0 or dots.

Does this solve all five grids together?

Yes. The solver treats the overlapping boxes as shared cells, so every placement is checked against all grids it belongs to.