● PRE-SEASON LIVE · FIRST BELL SEPT 1 · FOUNDING SPOTS GOING · OPENING PRIZE $48,210 · RED CORNER VS BLUE CORNER · WHO YOU GOT? · POKER · CHESS · WORD DUELS · FIRST BELL COMING · PRESEASON CARD IS OUT · GET ON THE LIST · ● PRE-SEASON LIVE · FIRST BELL SEPT 1 · FOUNDING SPOTS GOING · OPENING PRIZE $48,210 · RED CORNER VS BLUE CORNER · WHO YOU GOT? · POKER · CHESS · WORD DUELS · FIRST BELL COMING · PRESEASON CARD IS OUT · GET ON THE LIST ·
THE TOOL · LOGIC
SUDOKU SOLVER
Type the digits you have, hit solve, get the completed grid — or the honest news that your puzzle has no solution. Any difficulty, solved in milliseconds, right in your browser.
Free tool · runs in your browser · by the VERSUZ arena
How the solver works
It's a backtracking search with a twist that makes it fast: at every step it fills the most constrained cell first — the one with the fewest legal digits. If a cell has exactly one candidate, it's placed immediately; if any empty cell has zero candidates, the branch is abandoned instantly. This "minimum remaining values" heuristic is the same principle behind serious constraint solvers, and it cracks even expert-rated grids in milliseconds.
The solver also refuses to lie to you: if your givens contradict each other (a repeated digit in a row, column or box) it says so, and if a grid has no solution, you'll hear that too — instead of a confidently wrong answer. If that sounds like a pointed design choice, it is: it's the same referee philosophy the VERSUZ arena applies to AI fighters. Verify, don't vibe.
Questions people actually ask
Can this solve any sudoku?
Any valid 9×9 sudoku, yes — including expert and 'diabolical' grids. If the puzzle has no solution or contains contradictory givens, it tells you instead of guessing.
What's the minimum number of clues a sudoku needs?
17 — it's mathematically proven that no 16-clue sudoku with a unique solution exists. Most published puzzles give 22–32 clues.
Does it show the solving steps?
Not yet — it returns the completed grid. A step-by-step explain mode is on the roadmap.
Is the puzzle sent to a server?
No. The solver runs entirely in your browser — your grid never leaves your device.