Learn Sudoku in plain language. These articles use gentle, step-by-step explanations with small examples so students and puzzle enthusiasts can build confidence.
Browse all Sudoku solving techniques from beginner to expert. Learn Naked Singles, Hidden Singles, X-Wing, Swordfish, and more with step-by-step illustrated guides. Master every technique needed to solve easy through expert puzzles.
Learn crosshatching in Sudoku: scan rows and columns to eliminate where a number can go within a box. One of the most powerful beginner techniques — explained with step-by-step examples.
Learn the Last Free Cell technique: the easiest Sudoku solving method. When a row, column, or box has only one empty cell, the missing number goes there instantly. Perfect for beginners.
Learn the Naked Single Sudoku technique: how to find and use cells with only one possible candidate. Step-by-step guide with examples and practice puzzles for beginners.
Master the Hidden Single technique in Sudoku: find digits that can only go in one cell within a row, column, or box. Visual examples and step-by-step walkthrough for beginners and intermediates.
Learn how to find and use Naked Pairs in Sudoku. When two cells share the same two candidates, you can eliminate those numbers elsewhere. Detailed intermediate guide with examples.
Learn the Pointing Pair technique in Sudoku: when a digit inside a box is confined to one row or column, eliminate it from that line outside the box. Step-by-step guide with examples for intermediate solvers.
Learn Box/Line Reduction (Claiming) in Sudoku: when a digit in a row or column is confined to one box, eliminate it from the rest of that box. Intermediate technique explained with clear examples.
Learn the Naked Triple technique in Sudoku: when three cells in the same unit collectively hold only three candidates, eliminate those digits from the rest of the unit. Advanced guide with step-by-step examples.
Learn the X-Wing technique in Sudoku: when a digit appears in exactly two cells in each of two rows (or columns) forming a rectangle, eliminate it from the rest of those columns (or rows). Expert-level guide with examples.
Learn the Y-Wing (XY-Wing) Sudoku technique: a three-cell chain using a pivot and two pincers that enables powerful indirect eliminations. Expert guide with step-by-step examples.
Learn the Swordfish Sudoku technique: a three-row, three-column extension of X-Wing that eliminates a digit from entire columns. Expert guide with step-by-step examples for advanced solvers.
Understand Sudoku Note Validation: an automated tool that removes impossible pencil marks from your candidate lists, keeping your notes accurate so you can focus on solving techniques.
Learn when and how to use the Bruteforce method in Sudoku: a systematic trial-and-error approach with backtracking, used only when all logical techniques are exhausted.
The foundational Sudoku solving principle: systematically remove impossible candidates from cells based on row, column, and box constraints until the solution emerges.
Enter any Sudoku puzzle into our solver and watch it solved step by step — each move shows which technique is used and why.
Download free printable Sudoku puzzles to practice these techniques offline with pencil and paper.