Nonogram Solver
Enter your puzzle's row and column clues below, then click Solve Puzzle. Get an instant solution with step-by-step explanations for every deduction. Works for nonograms, picross, griddlers, and hanjie puzzles up to 30×30.
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Solution
Solving Steps
How to enter clues
- • Type numbers separated by spaces
- • Example:
3 1 2for a row with runs of 3, 1, and 2 - • Leave blank or enter
0for an empty row/column - • Click grid cells to pre-fill known cells
Techniques used
- Simple overlap — cells covered by all valid placements
- Block capping — complete runs get bounded
- Clue exhaustion — all fills accounted for
- Contradiction probe — advanced cell forcing
What is a nonogram?
A nonogram (also called picross, griddler, or hanjie) is a logic puzzle where you fill cells in a grid to reveal a hidden picture. Each row and column has a set of clues — numbers that tell you the lengths of consecutive filled-cell runs in that line. Using pure logic, every valid nonogram has exactly one solution.
How does this solver work?
Our solver uses constraint propagation — the same approach expert human solvers use. It analyzes each row and column independently, applies techniques like simple overlap, block capping, and clue exhaustion, then repeats until every cell is determined. For harder puzzles it uses contradiction probing to break ties. The step-by-step log shows you exactly which technique resolved each cell.
Tips for using the solver
- You can click individual grid cells to pre-fill cells you already know — the solver will respect them.
- If your puzzle comes from a book or app, count the clue numbers carefully — a mistyped clue is the most common cause of "no solution found".
- Large puzzles (20×20+) solve in under a second. The solver handles grids up to 30×30.
New to nonograms? Start with our beginner's guide or try one of our sample puzzles.