Solve it — and understand why

What every other solver gives you

Paste a puzzle into most solvers and you get one of two things. Either a completed grid — correct, useless for learning — or a log that reads X-Wing at R4C7, eliminate 5 from R4C2. That second kind is honest and precise, and it is written for someone who already knows what an X-Wing is. If you did, you would not be stuck.

What this one gives you

Paste your puzzle and press Explain every step. You get the whole solve, one card per move:

• what happened — R3C7 = 5, or R4C2 and R4C8 cannot be 5
• which technique — named the way the guides on this site name it
• why it is safe — one sentence of plain reasoning, not a term
• where to learn it — every move links to the full article on that technique

The reasoning sentence is the whole point. "Skyscraper: two parallel lines each have two homes for the digit and share one of them, so at least one tower top holds it" is something you can check against the board in front of you. "Skyscraper at C3–C7" is not.

How it decides

The solver applies techniques cheapest first: singles, then pairs and box-line work, then fish, then wings, then chains. It never reaches for an X-Wing while a hidden single sits in the corner, because the order it tries things in is the same order the site's technique guide teaches them in.

That ordering is also why the step count looks the way it does. A medium board is typically 50 steps and an expert board about 64 — not because expert is longer per move, but because more of the work is elimination rather than placement, and every elimination gets its own step.

The engine is the same one that rates every board in the game and filters every printable practice sheet. If the solver says your puzzle needs a skyscraper, that is the same judgement the difficulty label is built on.

What it will not do

It will not guess for you. If sixteen techniques cannot finish the board, the solver says so and shows you how far the logic got. That is the honest answer: some puzzles need a hand-built chain or a technique outside this ladder, and pretending otherwise would make every other step less trustworthy.

It does not check a grid against the original newspaper. It checks what you paste. If you transpose two digits, it will tell you the puzzle has no solution — which is usually the right conclusion, just about the input rather than the puzzle.

It does not store anything. The digits are parsed, solved and thrown away in your browser tab. No request leaves the page, which is also why it works offline once loaded.

Reading the output

Steps are numbered in the order they must be applied. A step that eliminates candidates is not optional — the next placement usually depends on it, so skipping an elimination and jumping to the placements will leave you staring at a board that does not move.

If a step's technique is unfamiliar, follow the link before reading the next card. The whole value of a solver like this one is that it can turn a stuck board into a lesson, and that only happens if you stop at the technique you did not recognise.