Sudoku guides for every solving stage

Learn the rules, choose a suitable difficulty and build a solving routine you can repeat on a new grid. SudokuGG guides explain what a pattern means, why an elimination is valid and where to practise it. They support the playable Classic Sudoku, Daily Sudoku, Printable Sudoku and Kalkudoku modules.

New to Sudoku? Read the rules, learn singles and complete a few Easy puzzles before studying pairs or X-Wing. Advanced names are useful only after the underlying logic is clear.

Start with the fundamentals

How to play Sudoku

A complete first lesson: rules, candidates, controls and a repeatable solving routine.

Sudoku rules

Understand rows, columns, 3×3 boxes and why Sudoku is logic rather than arithmetic.

Sudoku for beginners

Work through scanning, candidates and singles without guessing.

Naked and hidden singles

Learn the two essential placements that drive almost every solve.

Build an intermediate toolkit

Once direct placements become rare, candidate relationships let you remove possibilities while preserving the solution. After every elimination, return to scanning for singles.

Sudoku solving techniques

The main reference from basic scanning through advanced patterns, with a recommended learning order.

Pairs and triples

Use repeated candidate sets to clear other cells in the same house.

Locked candidates

Connect a box with a row or column to make safe eliminations.

X-Wing

Recognise a four-corner candidate pattern across two rows or columns.

Choose a level and practise

Difficulty is best understood as a solving path. The number of givens can offer a clue, but the techniques required to make progress are more important.

Easy Sudoku

Practise scanning and singles with more immediately useful givens.

Medium Sudoku

Add candidate notation and short elimination sequences.

Hard Sudoku

Expect fewer obvious moves and more interactions between houses.

Expert Sudoku

Use a careful candidate grid and advanced patterns without guessing.

Difficulty levels explained

Compare the four levels and decide when to move up or step back.

Accuracy and speed tips

Develop a consistent scan and reduce avoidable mistakes.

Common Sudoku mistakes

Diagnose guesses, missed candidates and contradictions before restarting.

Free online Sudoku

Understand the account-free browser experience and available controls.

Print and explore variants

Printable Sudoku guide

Create clean A4 practice sets, choose a layout and include solutions.

Kalkudoku rules

Combine Latin-square logic with addition, subtraction, multiplication and division cages.

How these guides are maintained

Rules and technique descriptions are checked against standard Sudoku constraints. Claims about notes, hints, printing and saved progress are compared with the working modules. We update a review date only after a meaningful content or product check. See the editorial policy for puzzle validation, authorship and corrections.

If an example is unclear or a feature description no longer matches the game, send the page address and the specific issue through the contact page. A precise correction is more useful than adding another near-duplicate article.

Play Classic Sudoku