Sudoku solver, step by step
Type the givens into the grid or paste 81 characters (digits, with 0 or a dot for empty cells). Next step shows one move at a time with the technique behind it; Solve lists every step and ends with the puzzle's level and rating. The solver runs in your browser, nothing is uploaded, and it uses the same logic as the game's hints, so every step is a deduction, never a guess.
Frequently asked questions
Which techniques does the solver use?
The same ones as the game's hints, tried in the same order: singles, locked candidates, pairs and triples, fish, wings, uniqueness patterns, chains, almost locked sets and forcing nets. Every step is a logical deduction, never a guess, and the hardest step sets the rating.
Does it work for any Sudoku?
For any puzzle with exactly one solution. Puzzles with no solution or with several are reported instead of solved, and a puzzle needs at least 17 givens.
Is my puzzle uploaded?
No. The solver runs entirely in your browser, offline as well. You can share a puzzle by adding its 81 digits to the address as ?p=.