Logic only · No guessing
How to solve Sudoku, step by step
One method, six moves, zero guessing. Learn it on the live Easy board — then climb the difficulty ladder.
Play now · easy
Tap a cell, then a number
The golden rule: never guess
Every well-formed Sudoku has exactly one solution, and every step toward it can be proven. If you ever feel the urge to guess, a technique you know already would resolve the position — you just haven't spotted it yet. The method below is ordered from fastest to most powerful; work top-down and stop as soon as a move appears.
The six-step solving method
- 1. Scan by digit. Pick one digit (1–9) and sweep the grid. Every row, column and box needs each digit once — existing placements eliminate most cells.
- 2. Place Naked Singles. If an empty cell has only one possible digit, fill it. This is the fastest safe progress on Easy boards.
- 3. Find Hidden Singles. If a digit can only go in one cell of a row, column or box, it must go there — even if the cell has other candidates.
- 4. Add pencil marks. On Medium and harder boards, write tiny candidate digits into empty cells. Marks turn invisible patterns visible.
- 5. Hunt pairs and pointing patterns. Two cells sharing the same two candidates (Naked Pair) lock those digits. A box confining a digit to one line removes it from the rest of that line.
- 6. Repeat until solved. Every placement creates new eliminations. Cycle through the steps — a valid Sudoku always cracks by logic, never guessing.
Which technique unlocks which difficulty
- Easy — Naked + Hidden Singles only
- Medium — add Naked Pair and pencil marks
- Hard — Pointing Pair, Box/Line Reduction
- Expert — X-Wing, Swordfish, XY-Wing
Keep learning
Full pattern library: Sudoku techniques · strategy ladder: Sudoku strategies · stuck? diagnostic guide · hard boards: solve hard Sudoku step-by-step.
FAQ
- What is the easiest way to solve Sudoku?
- Start with Easy boards and only use two moves: Naked Single (a cell with one candidate) and Hidden Single (a digit with one home in a unit). These two techniques solve most Easy and many Medium puzzles.
- Do you ever need to guess in Sudoku?
- No. A properly formed Sudoku has exactly one solution reachable by pure logic. If you feel forced to guess, you are missing a technique — usually a Hidden Single or a Naked Pair. Guessing is a habit, not a requirement.
- What order should I solve Sudoku in?
- Scan digit by digit first (fast eliminations), fill all singles you find, then add pencil marks and look for pairs. Finish one stubborn box or row completely before jumping around — locality beats random hopping.
- How long should a Sudoku take to solve?
- Easy: 3–8 minutes. Medium: 8–20. Hard: 20–45. Expert: 45+ or with advanced patterns. Speed comes from pattern recognition, not rushing — play one difficulty daily and times drop naturally.
- What do I do when I'm stuck on a Sudoku?
- Re-scan by digit (fresh singles appear), complete your pencil marks, then check for Naked Pairs and Pointing Pairs in that order. Our when-stuck diagnostic lists the exact technique you're probably missing.