Nonogram

How to play nonograms

A nonogram is a grid with numbers along the top and the left. Each number is a block of filled squares in that row or column, in order, with at least one empty square between blocks. Fill in squares until every row and column matches its numbers, and a picture appears.

• Read the clues. "3 1" on a row means a block of three filled squares, then, after one or more empty squares, a block of one. A clue of 0 means the whole line is empty.
• Fill what you are sure of. Tap or click a square to fill it. Drag along a row or column to fill several at once.
• Cross out what must be empty. Right-click, or switch to Cross and tap. Crosses are for your own notes; they help you see where blocks cannot go.
• Watch the clues fade. When a row or column matches its clue, its numbers turn pale, so you can see what is left.

Every puzzle here is made so that it can be solved by logic alone, line by line, and has exactly one answer. You never need to guess. If you are new to nonograms, how to solve nonograms shows the moves that do it, with diagrams.

Sizes and styles

• 5×5 takes a minute or two and is the best place to learn.
• 10×10 is the classic size.
• 15×15 and 20×20 are longer and need more care. On a phone, 20×20 squares are small; the grid scrolls sideways if it does not fit.
• Shapes pictures are made of solid areas. Scattered ones have more small blocks and gaps, so the clues are longer and you need more steps to pin each square down.

Every puzzle is new, made in your browser when you press New puzzle. Your progress is saved on this device, and Copy link to this puzzle gives a link that opens the same puzzle for a friend.

Hints and checking

Check shows any squares you have filled or crossed wrongly, in red. Hint first points out a mistake if there is one; if there is none, it finds a row or column whose clue decides a square you have not marked yet, marks it, and tells you which line it came from. The puzzle still counts as solved after a hint, and the result tells you how many you used.

Three tips

• Start with the big numbers. A block longer than half the line always covers its middle squares, whichever way it sits.
• Use the crosses. Once a line is finished, cross out the rest. A cross on one line often decides a square on the crossing line.
• Go back and forth. Work through all the rows, then all the columns, then the rows again. Each pass gives the next one something to work with.

Where nonograms come from

Nonograms were invented in Japan in 1987, independently, by the graphics editor Non Ishida and the puzzle maker Tetsuya Nishio. The British puzzle collector James Dalgety named them after Ishida: "nonogram" joins Non and diagram. The Sunday Telegraph printed them weekly from 1990, and they are also known as Hanjie and Paint by Numbers.

More logic puzzles: Sudoku and Killer Sudoku, or crack a quote in a cryptogram.