Sudoku Assistant/Solver -- Learn As you Go how to use this site

Save Blanks 1* 2* 3* 4* (grid) 5*a (fish) 5*b 5*c 6*a 6*b Challenge! ?? ???

3D Row: 1 2 3 4 5 6 7 8 9 Column: 1 2 3 4 5 6 7 8 9 reset
all recalculate strong edges remaining cells only
(It can take a few seconds for the model to load the first time.
Some Macintoshes may not be able to display the 3D model.)
Open in Andrew Stuart's solver

for the Sudoku community
by Bob Hanson


Sudoku Programmer Forum

Sudoku Players Forum

Glenn Fowler, ATT Research

Mark Becker

Angus Johnson




Ruud van der Werf

Sudoku Assistant/Solver -- by Bob Hanson, St. Olaf College
Standard View Advanced View 3D View Check Difficulty Analyze
Simple Table Medusa Strong Chain Compatibility Analysis

You can click on any cell to enter a number using the keypad. Entering a negative number removes that possibility. Or, after showing the possibilities, you can click on one to select that number.
Specific Numbers: pairs
Color: set clear
[steps] [chains]
possibilities 729x324 matrix
This page uses several fundamental techniques to solve any Sudoku that has a UNIQUE solution. This application will automatically cross-hatch scan. Optionally, you can turn on or off other methods. Red highlights will indicate that a particular value for a cell is not possible after the application of one of these techniques. For practice, check out the 12000 accompanying examples. See also the 12 Rules of Sudoku, a short essay on trial and error, and the solution to the Easter Monster puzzle solved by hand.

level: 3 4 5 6 7
  full   only   examples   
    chain options:               
You may want to turn on background printing. See note under "how to use this site"