Learn how to solve Sudoku

There are a large number of ways of solving Sudoku puzzles, these have accumulated over the years.

We have developed a complete set of free interactive guides to take you through each step of using all the key solution strategies.

Only Choice rule for gentle puzzles
Only Square rule for gentle puzzles
Single Possibility rule for gentle puzzles
Two out of Three strategy for gentle puzzles
Shared Subgroup rule for gentle and moderate puzzles
Naked Twin rule for moderate puzzles
Hidden Twin rule for tough puzzles
X Wing rule for tough puzzles
Swordfish rule for tough puzzles
Alternate Pair rule for very tough puzzles
Hook rule for very tough puzzles
Trial and error rule for any puzzle

Here are some example puzzles that are solved step by step using a mix of the strategies.

Gentle puzzle solved using the Two out of Three strategy
Gentle puzzle solved using Only Choice and Only Square
Moderate puzzle solved using some Twin and Sub-group logic
Challenging puzzle solved using Hook and Sub-group logic

Sudoku Dragon offers the best range of features for both the newbie and expert. It will solve and generate puzzles of all sorts of sizes. Read more...

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