Nonogram Solver
Stuck on a nonogram from a puzzle book, app, or another site? Enter its row and column clues below and this tool will solve it for you using the same logic engine that powers every puzzle on Nonogram Hub — or switch to "try it yourself" and solve it on an interactive board with the same fill/mark tools used across this site.
One line per row, numbers separated by spaces (e.g. "3 1"). Leave a line blank for an empty row.
One line per column, numbers separated by spaces. Leave a line blank for an empty column.
FAQ
How do I enter clues from a puzzle book?
Set the width and height to match the puzzle's grid, then type each row's numbers on its own line in the row clues box (in order, top to bottom), and each column's numbers on its own line in the column clues box (left to right). Separate multiple numbers in the same line with a space, like "3 1".
What if my puzzle doesn't have a unique solution?
A well-formed nonogram always has exactly one solution. If this tool reports more than one, either a clue was mistyped, or the source puzzle itself is flawed — double-check the numbers against the original.
Is there a size limit?
The solver is capped at a few seconds of computation to keep this page responsive for everyone. Very large or deliberately ambiguous grids may time out — most real puzzle-book nonograms solve in well under a second.
Can I solve the puzzle myself instead of having it solved for me?
Yes — after entering your clues, use "Try it yourself" to get the same interactive grid used across this site, with fill and mark tools, on your own puzzle's clues.
Can I print this puzzle?
Yes — after entering your clues, click "Download printable PDF" to get a blank grid with the clues laid out for solving on paper. If the puzzle has a unique solution, you can also download a version with an answer key on a second page.
How this solver works
Everything runs in your browser. The clues you type are never uploaded to a server — the solving engine is JavaScript executing on your own machine, so it works the same whether the puzzle came from a magazine, a screenshot, or a grid you designed yourself.
The engine reasons line by line, the same way a person does. For each row and column it works out every arrangement of blocks the clue still permits, then fills in the cells that are filled in every one of those arrangements, and crosses out the cells that are empty in every one of them. Because deducing a cell in a row also constrains the column crossing it, the process repeats until nothing new can be deduced. Where pure deduction stalls, it falls back on a bounded search rather than guessing blindly.
It does not stop at the first answer it finds. It deliberately looks for a second, different solution — which is what lets it tell you whether your clues have exactly one answer, more than one, or none at all. A nonogram with two valid solutions is a broken nonogram: usually a mistyped number, occasionally a genuine flaw in the source puzzle. Solving is capped at a few seconds so the page stays responsive, and nearly every real puzzle-book nonogram finishes well inside that.
This is the same engine every puzzle on Nonogram Hub is validated with before it is published — which is why the daily puzzles are always solvable by logic alone, with no guessing required.
Learn to solve them yourself
A solver is useful for checking an answer or rescuing a puzzle you're stuck on — but nonograms are more fun when you don't need one. These guides cover, step by step, the techniques the engine above is applying automatically: