Pick a size from the tabs above the board. There are 20 puzzles at each of 5×5, 10×10, 15×15, 20×20 and 25×25, and the pictures were drawn by us as pixel art: a fish and an anchor at 10×10, an owl and a lighthouse at 15×15, a steam train and a castle at 20×20, among others.
How the clues work
- Each number is the length of an unbroken block of shaded cells in that row or column.
- The blocks appear in the same order as the numbers, reading left to right for rows and top to bottom for columns.
- There is at least one empty cell between two blocks. Empty cells may also sit before the first block and after the last.
- A row clued 0 has no shaded cells at all.
- The puzzle is solved when every row and every column matches its clue. Marking the cells you know are empty with a cross is optional, but it helps.
Where to begin on any grid
Look for big numbers first. In a 15-wide row, a clue of 11 must cover the middle 7 cells whichever way you slide it: pushed fully left it covers cells 1 to 11, pushed fully right it covers 5 to 15, and cells 5 to 11 are shaded in both. The general sum is twice the clue minus the width, so a 7 in a 10-wide row fixes 4 cells.
Add up clues with several numbers the same way. A row of 3 2 4 needs 3 + 1 + 2 + 1 + 4 = 11 cells, so in an 11-wide line it fills the whole row, and in a 15-wide line it leaves only 4 cells of slack. Each finished line then hands you crosses and shaded cells for the lines that cross it, so work back and forth between rows and columns.
What the sizes and levels ask of you
The 5×5 puzzles are short warm-ups, half easy and half medium, solved by counting and edge work alone. At 10×10 the full range opens up: 9 easy, 5 medium, 4 hard and 2 expert. The 15×15 set leans easier (11 easy, 5 medium, 4 hard) and suits a coffee break. At 20×20 the levels are spread evenly, with 4 expert, and the 25×25 set has no easy puzzles at all: 7 medium, 7 hard and 6 expert.
Those levels come from the techniques our grader needed. Easy grids yield to counting from the edges, as in the 11-in-15 example. Medium grids need more edge reasoning: a shaded cell near the border or next to a cross glues a block in place, so you can extend it or cross off cells it can't reach. Hard grids contain at least one line where only full line logic works, which means weighing every legal arrangement of that line and keeping the cells they all agree on. Expert grids need one probe: assume a cell, follow the consequences until a line breaks, and the cell must take the other value. We never go deeper than one such step, and any grid that would need guessing beyond it is thrown away.
Guides, a solver and printables
The how to solve nonograms guide works through a full grid, and nonogram solving tips collects the patterns that come up again and again. To check a puzzle from a book or newspaper, enter its clues in the nonogram solver.
Every size is available on paper too: the printable nonogram packs have the answers on the last pages, and there is a large print edition with bigger squares. For one fresh 15×15 every day, open the daily nonogram.