Solve any standard 9×9 Sudoku online for free. Fast constraint-propagation solver with one-click solve — no downloads required. No sign-up & unlimited. Type in the numbers you know, click Solve, and our tool will instantly fill in the whole puzzle.
Enter digits (1-9) and press Solve. Cells with initial numbers are highlighted.
This tool solves standard 9×9 Sudoku using backtracking. It runs fully in your browser.
- Solve or fill only certain (provable) moves before searching
- Works entirely in-browser — no sign-up or downloads
- Sample puzzles and keyboard navigation
- Clear, copyable board and printable results