Type a puzzle in, paste it, or photograph it — then get the solution along with the reasoning that produces it.
You can fill the grid by hand, clicking cells and choosing digits from the keypad or typing 1–9 directly. Hold Ctrl to select several cells at once, and use Delete or Backspace to clear. For a puzzle you already have as text, paste an 81-character string and the grid fills itself.
The third route is a photograph. The importer runs optical character recognition in your browser, reads the givens off a picture of a printed grid, and drops them into the solver. Recognition is not flawless on a low-contrast newspaper scan, so check the imported digits before solving — a single misread given produces a puzzle with no valid solution.
The solver does not just hand you a filled grid. It reports whether the puzzle is valid and has a unique solution, grades its difficulty on the same five-tier scale used across the site, and can walk the deduction step by step so you can see why each digit goes where it goes.
That grading is the same engine that classifies the platform's 146,764 puzzles, so a puzzle graded Extreme here is genuinely Extreme by the site's own standard: Easy needs only Naked Singles, Medium adds Hidden Singles and Locked Candidates, Hard brings Pairs, Triples and Unique Rectangles, Extreme reaches X-Wings, Skyscrapers and Coloring, and Diabolical demands XY-Chains, Finned Fish and ALS.
Solving a puzzle for you is the least interesting thing the solver does. Each step is tied to a named technique, and every one of those techniques has a full guide in the Learning Hub — so when the solver tells you a Skyscraper resolves the cell you were stuck on, you can go and learn the pattern rather than just accept the digit.
Any valid puzzle you enter can also be handed straight to the play board, so you can attempt it properly with the timer running instead of watching it get solved.
The solver deliberately refuses any puzzle that is currently live in a competitive event — an active tournament, an in-progress duel, the ranked daily or any Daily Triple leg. That block is global: it applies across every device and browser, not just yours.
Matching is done on the givens, so pasting a partially filled board does not get around it. The check also fails closed: if the lookup itself errors, the solver refuses rather than risking an answer to a live competitive grid. Once the event ends, the puzzle unlocks normally.
Yes, completely, with no account required. There is no limit on how many puzzles you can solve.
It solves any valid 9×9 Sudoku with a unique solution. If a puzzle has no solution or more than one, it tells you rather than guessing.
Yes. The image importer runs OCR in your browser to read the givens. Verify the recognised digits before solving, especially on low-contrast scans.
Yes. It can step through the solve technique by technique, and every technique it names has a full guide in the Learning Hub.
Puzzles that are live in a tournament, duel, ranked daily or Daily Triple are blocked globally while the event runs. This keeps competitive play fair, and it unlocks once the event ends.