▦Nonogram

About this tool

Choose a picture puzzle, such as a heart, house, smiley, tree, cup or arrow, or a random grid of 5×5, 10×10 or 15×15. Click or tap squares to fill them, right-click or switch the tap mode to mark squares you know are empty, and drag to fill several in a row. Clue numbers turn green when their line matches, and the puzzle celebrates when every clue is satisfied.

How to solve a nonogram

Each number is a run of filled squares in that row or column, in order, with at least one empty square between runs. "3 1" means three filled squares, at least one gap, then one more. Solve with logic rather than guessing. Overlap is the first trick: in a row of 10, a single clue of 8 must cover the middle six squares wherever it sits, because it can start no further left than square 1 and no further right than square 3. Lines whose clues fill the whole width, counting the gaps, can be filled completely, so "4 5" in a row of 10 has only one arrangement. Marking known empty squares with × is half the work, because it pins down where runs can and can't go. Then switch between rows and columns, using each new square as a clue for the crossing line. The hand-made pictures always have a single answer. Random puzzles occasionally allow more than one, so any grid that matches every clue counts as solved. Sudoku, minesweeper and the jigsaw puzzle are other logic games, and How to play Minesweeper properly covers similar deduction.

Frequently asked questions