Features

Pencil Marks

The main feature of this program is its excellent handling of pencil marks. You have a full manual mode or any of nine different levels of automatic modes. You can switch between the different modes easily, so if you're stuck while trying to solve the puzzle, you can jump from manual mode to automatic and then back again. You can also copy the pencil marks from any of the automatic modes to the manual mode and then work on the puzzle from there.

Manual Mode

Automatic Mode

Lock the Puzzle

Once you have finished setting up a puzzle, you can lock the numbers to prevent accidentally erasing any of the starting numbers. The numbers turn grey to indicate which numbers are locked, with subsequent numbers entered in black. Also once you've locked the board, it will automatically rate the puzzle and tell you the highest level of strategy required to solve it.

Highlighting of Numbers

When you've chosen a number from the number bar, it will automatically highlight in green the squares that contain that number. It will also highlight in blue the squares that contain that number as a pencil mark. You can choose to highlight multiple numbers as well as exclude from highlighting squares that contain certain numbers.

Highlighting of Errors

When you've chosen a number from the number bar, and you've placed a number incorrectly on the board, it will highlight in red the squares that become invalid due to the placement of that number. In the example below, placing a six in the third region resulted in two squares becoming invalid.

Easy Handling of Forks

You can back up your puzzle when you come to a fork. All numbers on the board will then become grey so you know which numbers were done before the fork. If you choose a wrong fork, you can restore your puzzle and try a different fork.

Undo and Redo Steps

You can undo steps all the way back to the beginning of the puzzle or back to when it was last locked, whichever was most recent. You can also redo steps if you've gone back too far.

Check Puzzles

When you're solving a puzzle and you want to see if you're doing it correctly, you can check the puzzle to see if there is an error somewhere.

Save Puzzles

If you get interrupted while working on a puzzle, you can save the puzzle and come back to it later. The native "sds" file is capable of saving both the numbers on the board as well as your manual pencil marks.

Import and Export Puzzles

If you come across puzzles on the Internet that are in text form or in a table, you can save them as text files or csv files and then import them into Su Doku Solver. You can also export your puzzle to either a text file, for use with a word processor, or a csv file, which can then be imported into your spreadsheet application of choice.

Print Puzzles

You can print your puzzles with or without the pencil marks to work on away from the computer. You also have the option of printing six copies of the same puzzle to a page if you want to try various forks or just want to distribute them to friends and family.

Create Puzzles

Create all sorts of new puzzles with control over the symmetry and the difficulty level. All puzzles created by Su Doku Solver can be solved using only logic and will have only one solution.

Find Solutions to Fiendish Puzzles

The built-in solver can solve any su doku puzzle, whether it has a unique solution or not. If it has multiple solutions, it will search for all solutions and then write them to a log file.