Sudoku Solver – Instantly Solve Any Sudoku Puzzle
Our Sudoku Solver is designed to help you solve any Sudoku puzzle, whether you’re stuck on a single cell or want to see the full solution. Use it to check your work, get hints, analyze difficulty, and practice advanced solving strategies.
How to Use the Sudoku Solver
1. Enter Your Puzzle:
The first step is to fill the grid with your current puzzle. There are multiple options to make completing this step easier which are explained in the puzzle management section below.
2. Choose a Solve Option:
- Solve Cell: Select a cell and click this button to solve just that cell. This will try to solve that specific cell using only the current board information. Even though the puzzle may be valid it may not be possible to currently solve for that specific cell.
- Solve: Instantly solve the entire puzzle. Great way to check if the puzzle is valid.
- Solve Partially: Solve the puzzle step-by-step according to your preferences. This allows you to walk through the solution one step at a time or show you that the puzzle is indeed unique and solvable.
Sudoku Solver: Helper & Analysis Features
Check: Verify if your puzzle is valid, solvable, and has a unique solution.
Difficulty Order: These are the techniques that are used to solve puzzles. You can determine which ones are used and in which order to help base the solving of the puzzle on your preferred techniques These are the techniques that can be used:
- Techniques: Naked Single, Hidden Single, Naked Pair, Hidden Pair, Pointing Pairs, Naked Triple, Naked Quad, Pointing Triples, Hidden Triple, Hidden Quad, X-Wing, Swordfish, Jellyfish, XY-Wing, XYZ-Wing. Learn about these strategies at our sudoku techniques page.
Hint: Get a hint for the next logical step—either a cell to solve or candidates to eliminate.
Generate: Automatically fill in all possible candidates for empty cells.
Remove: Clear all candidates from the grid.
How this Solver Takes Puzzles
There are multiple ways that you can input a Sudoku puzzle into this solver.
The first is to enter the digits for your puzzle directly into the grid above. You can also paste a string of values, with empty cells being represented as dots reading left to right.
need Sudoku puzzles to solve?
You can pull from our free Sudoku puzzles that you would find when playing on Sudoku Pulse. If you want to first try a puzzle first play Sudoku on our main page.
When to Use a Sudoku Solver
A solver is most valuable as a learning tool, not a shortcut. Here are the best use cases:
- Stuck on one cell. Use “Solve Cell” to get past a single sticking point without spoiling the rest of your solve.
- Learning new techniques. Use “Solve Partially” to see which technique the solver applies at each step. This teaches you patterns you can spot in future puzzles.
- Checking puzzle validity. Creating your own puzzle? Use “Check” to verify it has exactly one unique solution.
- Difficulty analysis. The solver reveals which techniques a puzzle requires, giving you insight into its true difficulty rating.
- Post-solve review. After finishing a puzzle, run the solver to see if there was a more efficient path you missed.
For a complete guide to getting the most from this tool, see our How to Use a Sudoku Solver article.
Supported Solving Techniques
The solver applies these techniques in order from simplest to most advanced:
| Technique | Difficulty Level | What It Does |
|---|---|---|
| Naked Single | Easy | Places a digit when a cell has only one candidate |
| Hidden Single | Easy | Places a digit when it can only go in one cell in a unit |
| Naked Pair | Medium | Eliminates candidates based on two cells sharing two candidates |
| Hidden Pair | Medium | Locks two digits to two cells in a unit |
| Pointing Pairs | Medium | Eliminates candidates based on box-line intersections |
| Naked Triple | Medium–Hard | Extends pair logic to three cells |
| Naked Quad | Hard | Extends pair logic to four cells |
| Pointing Triples | Hard | Extended pointing for three cells |
| Hidden Triple | Hard | Locks three digits to three cells |
| Hidden Quad | Hard | Locks four digits to four cells |
| X-Wing | Hard–Expert | Fish pattern across two rows and two columns |
| Swordfish | Expert | Fish pattern across three rows and three columns |
| Jellyfish | Expert | Fish pattern across four rows and four columns |
| XY-Wing | Expert | Three bivalue cells forming elimination pattern |
| XYZ-Wing | Evil | Extended wing with three candidates in the pivot |
Tips for Using the Solver Effectively
- Try solving first. Always attempt the puzzle yourself before reaching for the solver. The struggle is where learning happens.
- Use Solve Partially, not Solve. Stepping through one technique at a time teaches you far more than seeing the complete solution instantly.
- Pay attention to technique names. When the solver names a technique you do not know, visit the linked technique guide to learn it. This is the fastest way to expand your toolkit.
- Re-attempt after learning. After the solver shows you a technique, reset the puzzle and try to find that same pattern on your own.
This Sudoku Solver is the perfect tool to help you solve the next cell on a difficult puzzle that you are working on. This is a good way to practice as you will see how more difficult strategies appear in puzzles and learn how to solve for them. This tool is also good if you want to do a quick check to find out if a puzzle is solvable, and has one unique solution!