Sudoku Sudoku Helper: Learn to Solve Any Puzzle
Most Sudoku solvers just give you the answer. Our Sudoku Helper teaches you how to get there. It identifies the easiest technique available at each step, highlights the relevant cells, explains the logic, and links to a detailed guide — so you actually improve at Sudoku instead of just seeing the solution.
The helper scans the grid for 17 different solving techniques, in order from easiest to hardest. When it finds one that applies, it highlights the cells involved, explains what to do, and lets you apply the step with one click. Pencil marks are managed automatically.
📋 How to Use the Sudoku Helper
- Enter your puzzle — Click a cell and type a number, or paste an 81-character string and click Import.
- Press "Next Hint" — The first press fills in pencil marks automatically. Each subsequent press finds the next applicable technique.
- Read the explanation — The hint panel shows the technique name, a description of the logic, and a link to a full article.
- Press "Apply Hint" — Executes the placement or elimination. Pencil marks update automatically.
- Repeat — Keep pressing Next Hint → Apply Hint to solve the entire puzzle step-by-step.
Use the technique dropdown to practise a specific strategy. Select "X-Wing" and the helper will only look for X-Wing patterns, ignoring easier techniques — perfect for targeted practice.
🎯 Techniques Detected (Easiest → Hardest)
The helper checks for these 17 techniques in order. Click any link to read the full strategy guide:
- Naked Single — A cell with only one possible candidate.
- Hidden Single — A digit that can only go in one cell within a unit.
- Pointing Pair — Candidates in a box confined to one row or column.
- Box/Line Reduction — Candidates in a row/column confined to one box.
- Naked Pair — Two cells in a unit sharing the same two candidates.
- Hidden Pair — Two candidates appearing only in the same two cells within a unit.
- Naked Triple — Three cells sharing exactly three candidates.
- Hidden Triple — Three candidates confined to three cells in a unit.
- X-Wing — A fish pattern on two rows and two columns.
- Swordfish — A fish pattern on three rows and three columns.
- Jellyfish — A fish pattern on four rows and four columns.
- XY-Wing — A pivot cell with two bivalue pincers.
- XYZ-Wing — Like XY-Wing but the pivot has three candidates.
- W-Wing — Two bivalue cells connected by a strong link.
- Skyscraper — Two strong links on the same digit sharing one endpoint.
- Simple Colouring — Alternating chains of a single digit.
- Unique Rectangle — Exploits the rule that a valid puzzle has a unique solution.
If you're just starting out, the helper will mostly use Naked and Hidden Singles — the bread and butter of Sudoku solving. As you tackle harder puzzles, you'll see advanced techniques like X-Wings and Swordfish appear. Each hint links to a full article explaining the strategy in detail.
🔗 From Helper to Solver
If you get stuck and just want the answer, click the puzzle's export string and paste it into our Sudoku Solver. Or copy a puzzle from the solver to the helper using the ?puzzle= URL parameter.
🎮 More Sudoku Tools & Puzzles
- Sudoku Solver — Get the instant complete solution for any puzzle.
- Classic 9×9 Sudoku — Play puzzles at four difficulty levels.
- Killer Sudoku — Cage sums instead of standard givens.
- Blog & Tips — In-depth strategy guides for every technique.
Frequently Asked Questions
The Sudoku Helper is a free tool that teaches you how to solve Sudoku puzzles step-by-step. Instead of just showing the answer, it identifies the easiest solving technique available and explains why it works, with highlighted cells and links to detailed guides.
The helper detects 17 techniques in order of difficulty: Naked Single, Hidden Single, Pointing Pair, Box/Line Reduction, Naked Pair, Hidden Pair, Naked Triple, Hidden Triple, X-Wing, Swordfish, Jellyfish, XY-Wing, XYZ-Wing, W-Wing, Skyscraper, Simple Colouring, and Unique Rectangle.
When you press "Next Hint" for the first time, the helper automatically fills in pencil marks (small candidate numbers) for every empty cell, showing all possible digits. As you apply hints, pencil marks are updated automatically — you never need to manage them manually.
Yes! Use the dropdown menu above the controls to select a specific technique. The helper will then only search for that technique, ignoring easier strategies. This is great for practising a particular solving method on puzzles you know require it.