How to play Nonogram

Nonograms — also known as Picross, Griddlers, or Hanjie — are picture logic puzzles where a hidden image emerges from a grid of black and white squares. There's nothing to memorise and no guessing required: the numbers around the edge of the grid contain everything you need to deduce, square by square, which cells are filled and which stay blank.

Goal

Fill in exactly the cells that belong to the hidden pattern, leaving the rest empty, so the grid matches the picture the clues describe. Get every cell right and the puzzle is complete. Choose Easy for a friendly 5×5 grid or Medium for a meatier 10×10 to work up to.

Reading the clues

The numbers beside each row and above each column give the lengths of the consecutive filled-cell runs in that line, listed in order. A clue of "3 2" means a block of three filled cells, then at least one empty cell as a gap, then a block of two — in that sequence. A clue shown as "·" (or 0) means the entire line stays empty. The clues never tell you where the blocks start, only their sizes and order; pinning down their positions is the puzzle.

Controls

• Tap or click a cell to fill it; tap it again to clear it.
• Right-click (or long-press on touch) marks a cell with an X, your note that it's definitely empty.
• Use the X marks freely — they don't affect the solution, but they keep your reasoning visible and stop you from re-checking the same dead ends.

Strategy

Begin with the lines whose clues nearly fill the whole length — a clue of "5" in a five-wide row is entirely filled, an instant win. Next hunt for overlaps: in a five-cell line with the clue "3," the block can only slide so far either way, so the centre cell must be filled no matter where the run sits. Cross off impossible cells with X as you confirm gaps, then let solved columns feed back into the rows and vice versa. Working the two directions against each other is what cracks even large grids.