What is a Sudoku solver?
It takes a partially filled grid and finds the complete solution. Our solver applies 7 human-style techniques (naked singles, hidden singles, pairs, pointing pairs, box-line reduction, hidden pairs, and naked triples) before falling back to backtracking with constraint propagation.
Can this solver handle different Sudoku variants?
Four: classic 9×9, mini 6×6, Killer Sudoku (cage constraints), and Diagonal Sudoku (diagonal constraints). Pick the variant tab before you enter your puzzle.
How does the step-by-step solving work?
It applies techniques in difficulty order. Each step highlights the cells involved, names the technique, and explains the reasoning. A solid way to learn strategies you haven't encountered before.
What does Validate do?
Two checks: first, are there any conflicts (duplicate digits in rows, columns, or boxes)? Second, does the puzzle have exactly one solution? Both must pass for Validate to give the green light.
Is there a formula to solve Sudoku?
No single formula, but there's a systematic approach. Start with naked singles and hidden singles, then move to pairs and intersections. The step-by-step solver shows exactly this progression. When human techniques stall, the solver uses backtracking with constraint propagation - an algorithm that is guaranteed to find a solution if one exists, since mathematicians have proven every valid Sudoku has exactly one.
What is the best strategy for solving Sudoku?
Naked and hidden singles first - always. Scan every row, column, and box for cells with one possible digit. Then hunt for pairs and intersections. Pencil marks help you track what's left. That's the exact progression the solver uses.
What is the trick to solve Sudoku?
Elimination over guessing. Scan for naked singles (cells where only one digit works), then hidden singles (digits that only fit one cell in a unit). Get comfortable with these two and you'll handle most easy-to-medium puzzles without ever needing to guess.
How do you solve a Sudoku puzzle?
Scan for naked singles first - cells with just one valid digit. Then look for hidden singles - digits that only fit one spot in a row, column, or box. Harder puzzles call for naked pairs, pointing pairs, and box-line reduction. The solver demonstrates all of these, step by step.
