Solvers
Puzzles
Latest Apps
Str8ts
Other

 Jigsaw Sudoku Solver Please report any bugs. Tested in IE, Firefox, Safari and Chrome Feedback: Form and User Comments/Questions Here
 Candidates can be Edited or Highlighted / Shown
Enter clues or solutions
 1 2 3 4 5 6 7 8 9
 Auto Tab Auto Clear
Clues+Solved: 0/81
 Step 1: Choose the 'shape' Andrew Stuart 1 Andrew Stuart 2 Andrew Stuart 3 Andrew Stuart 4 Andrew Stuart 5 Andrew Stuart 6 Andrew Stuart 7 Andrew Stuart 8 Moonlotus Onion Double Mirror Cyndie Tornado Cross Worm Cabbage Stripes H Wednesday ZigZag Legoman Offside Anonymous 1 Tim Tang Andrew Stuart New 24 Andrew Stuart New 25 Andrew Stuart New 26 Andrew Stuart New 27 Andrew Stuart New 28 Step 2: Pick an example here Example 1 Example 2 Example 3 Example 4

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 www.sudoku.org.uk 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
to retrieve the latest script files.
 A B C D E F G H J
Version 2.06
Coordinate system: Letter/Number rYcX

 1 2 3 4 5 6 7 8 9
 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

## Welcome to my Jigsaw Sudoku page

I am pleased to reveal this latest Sudoku Solver - one for Jigsaw sudokus. 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 strategies pertain to Jigsaws, but in the current version I have removed Uniqueness tests until I can check the algorithms more properly. However, you will rarely need an extreme strategy since they are often defeated using no more than Pointing Pairs and Box/Line Removal - simple because the shapes of the boxes lead to more opportunities for these strategies. Also, the Law of Leftovers is an excellent candidate eliminator. Documentation on this to follow.

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 new 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.

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.

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.