🧩 Sudoku Solver

Input or upload – solved in milliseconds.

Sudoku Puzzle

Upload Sudoku Image

Drop your Sudoku image here

or click to browse

Supports PNG, JPG, JPEG

How It Works

Our Sudoku solver uses a backtracking algorithm with constraint propagation to efficiently solve puzzles. The algorithm works by:

  1. Finding the next empty cell in the grid
  2. Trying numbers 1-9 that don't violate Sudoku rules
  3. Recursively solving the remaining puzzle
  4. Backtracking when no valid number can be placed

For image recognition, we use Tesseract.js OCR to detect digits in uploaded images. The system preprocesses images to improve recognition accuracy and maps detected digits to the corresponding grid positions.

Frequently Asked Questions

How accurate is image recognition?

Our OCR system achieves 85-95% accuracy on clear, well-lit images. For best results, ensure the image is high contrast with clearly visible digits.

Does this work on mobile devices?

Yes! The solver is fully responsive and works on all devices. You can take a photo of a Sudoku puzzle and upload it directly from your phone.

Can it solve hard puzzles?

Our backtracking algorithm can solve any valid Sudoku puzzle, regardless of difficulty level, typically in under 100 milliseconds.

Is my data stored or shared?

No, all processing happens locally in your browser. Images and puzzles are never uploaded to our servers or stored anywhere.