UtilityBaseGenerators
Sudoku Solver & Generator
Solve any Sudoku puzzle instantly, or generate fresh puzzles at your chosen difficulty to play or print.
Updated July 10, 2026
How to use the sudoku solver & generator
- 1Pick a difficulty and click Generate, or type your own puzzle.
- 2Fill the grid, using each digit 1–9 once per row, column, and box.
- 3Click Solve to complete it, or play it yourself.
- 4Print a generated puzzle to solve on paper.
Common uses
- Solving a puzzle you're stuck on
- Generating puzzles to play
- Printing Sudoku for offline solving
- Checking your solution is valid
Frequently asked questions
How does the Sudoku solver work?
It uses backtracking: it places a candidate digit in the first empty cell, moves to the next, and backs up whenever it reaches a dead end. This systematically finds the unique solution if the puzzle has one, in a fraction of a second.
Are the generated puzzles solvable?
Yes. Each puzzle is created from a complete, valid solution by removing cells only while exactly one solution remains, so every generated puzzle is fair and can be solved by logic without guessing.
Can I print a puzzle?
Yes. Generate a puzzle at your chosen difficulty and use the Print button to print a clean copy to solve on paper.
About this tool
This Sudoku tool does both jobs: type in a puzzle and it solves it instantly with a backtracking algorithm, or generate a brand-new puzzle at easy, medium, hard, or expert difficulty to play on screen or print. Generated puzzles are made by removing cells from a complete solution only while exactly one solution remains, so every puzzle is fair and solvable by logic alone. It flags conflicts if your entries can't be solved. Everything runs in your browser.
Like most tools on UtilityBase, the sudoku solver & generator runs entirely in your browser — nothing you enter is uploaded or stored on a server. It's free to use with no account required. Browse more generators here.
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