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Jigsaw Sudoku Solver
Please report any bugs and feedback welcome

Candidates can be Edited or Highlighted / Shown
Enter clues or solutions
1 2 3 4 5 6 7 8 9
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Clues+Solved: 0/81
Step 1: Choose the 'shape'
Step 2: Pick an example here

Quick help: The differences

Jigsaw Sudokus are the same as normal sudoku except for the shapes of the boxes. Some strategies cannot be used (see below) but there is one important addition: The Law of Leftovers.

In order to use this solver you need to pick the correct grid shape from the list above. Only then type the numbers into the small grid, use the Import button or pick an example from the example list.

There are 20 Jigsaw shapes as used on and four interesting examples for each shape, 80 examples in total.

For all other help guides for the solver, see the Sudoku Solver.

Please report any bugs - Thanks.

If you are getting errors please
clear your browser cache
to retrieve the latest script files.
Version 2.09
See the Strategy Home Page for strategy guides.
Coordinate system: Letter/Number rYcX

Check for Solved Cells   
Show Possibles  
1: Hidden Singles  
2: Naked Pairs/Triples  
3: Hidden Pairs/Triples 
4: Naked Quads 
5: Pointing Pairs  
6: Box/Line Reduction  
Tough Strategies
7: Double Pointing Pairs  
8: Double Line/Box Reduct.  
9: Law of Leftovers  
10: X-Wing  
11: Simple Colouring  
12: Y-Wing  
13: Swordfish  
14: XYZ Wing  
Diabolical Strategies
15: X-Cycles  
16: XY-Chain  
17: 3D Medusa  
18: Jellyfish  
19: WXYZ Wing  
Extreme Strategies
20: Grouped X-Cycles  
21: Altern. Infern. Chains 
22: Digit Forcing Chains  
23: Nishio Forcing Chains 
24: Cell Forcing Chains  
25: Unit Forcing Chains  
26: Almost Locked Sets  
27: Death Blossom  
28: Pattern Overlay Method  
29: Quad Forcing Chains  
"Trial and Error" 
30: Bowman Bingo 

Box numbers refered to in
strategy results:

Want to know what shape is what?
View the Jigsaw Shape List
Free Sudoku and Str8ts for Print

Welcome to my Jigsaw Sudoku page

In many ways Jigsaw's are even more interesting than normal Sudokus, although they have not been studied as much.

All bar a few of the classic Sudoku strategies pertain to Jigsaws, but in the current version I have removed Uniqueness tests since it is very difficult to determine valid 'Deadly Rectangle' in the jumble of shapes. However the non square shapes open up the opportunity to use some neat strategies only found in Jigsaws such as the Law of Leftovers, Double Pointing Pairs and Double Line/Box Reduction. Also puzzles are often defeated using simple Pointing Pairs and Box/Line Removal as the shapes of the boxes lead to more opportunities for these strategies.

I have now added a page showing all the Jigsaw Shapes

All feedback, comments, arguments, bug reports and strategy ideas are welcome. There is a FEEDBACK form with a column displaying comments and questions. Many thanks to all the people who have done so and helped improve this solver.

New in version 1.99 (April 9th 2014)
Unchecked strategies are now saved in a cookie.

New in version 1.95 (June 3rd 2013)
Introducing Double Pointing Pairs and Double Line/Box Reduction.

New in version 1.94 (November 21th 2012)
Re-wrote Pointing Pairs for Jigsaws - obvious new case.

Latest version 1.86 (July 16th 2012)
Updated the basic strategies to report more clearly, adding green candidates for those numbers that cause other candidates to be removed. Brought it into line with the Sudoku solver.

Latest version 1.85 (May 12th 2012)
On the small board for number entry I have added an option that automatically clears off candidates as numbers are added. Also, changes to the small board are automatically saved.

New in version 1.79 (June 21st 2011)
Added some new 'shape' patterns - see the end of the example pull down list. These are used in the new Jigsaw Sudoku Puzzle Packs. The examples here are gentle, moderate, tough and extreme - four each for each new shape pattern.

Version history here

New in version 1.38 (November 21st 2006)
Release of the Jigsaw Solver

Solver created on 31-Mar-2007.

This page was last modified on 11-Jun-2023
All code and design is copyright and for personal use only and may not be reproduced elsewhere.
Copyright Andrew Stuart @ Syndicated Puzzles, 2005-2023