Nonogram

Pick a size and a level and a fresh board is built in your browser, checked, and put on screen. No limit, no account, nothing uploaded.

A puzzle that ends in a picture

Down the left of the board and along the top sit lists of numbers. Each list belongs to one line and gives the lengths of the filled stretches in that line, in the order they appear, with at least one blank cell between consecutive stretches. A row labelled 4 2 holds a run of four somewhere, then a gap, then a run of two, and nothing else. Where those runs sit is the entire puzzle.

Work every line out and the cells you have filled turn into something — an animal, an object, a symbol. That reveal is what separates this puzzle from every other one on this site, and it is why the boards you meet on the daily and in the archive are drawn by hand rather than generated. The practice boards on this page are generated, and they are honest about it: they are patterns, not pictures, and they exist so that there is no limit on how many you can play.

The puzzle is Japanese and dates from the late nineteen-eighties. It travels under a number of names: hanjie in British newspapers, paint by numbers in magazines, and — as other people’s registered brands rather than as ordinary words — Picross and Griddlers. This site calls it a nonogram, which is the plain descriptive term and belongs to nobody.

Filling, crossing, and why the crosses are half the work

Drag across a run of cells to fill them, and drag again over filled cells to clear them. Switch to the other mode and the same drag marks cells as definitely blank instead. On a mouse you can skip the switch: the right button crosses. Every drag counts as one move, so one press of undo takes back a whole sweep rather than making you tap it away a cell at a time.

Marking blanks feels like bookkeeping and it is not. A crossed cell is a wall, and walls are what let you split a long line into shorter pieces and hand each number to a piece it fits in. Two of the five arguments this puzzle needs depend on the walls being on the board, and one of them can do nothing whatever without them. A solver who fills and never crosses ends up re-deriving the same emptiness a dozen times and concludes the board is stuck.

The keyboard does all of it. Arrow keys move, F or the space bar fills, X crosses, and backspace puts a cell back to undecided. Holding shift while you move extends the last action along the line, which is the keyboard version of a drag.

What the size and the level each decide

Size decides how long the board takes and how much of it you can hold in your head at once. A five is a minute. A ten is a coffee. A fifteen is the size most published boards use and is the one to settle on. A twenty is an evening, and its lines are long enough that a single number can sit in a hundred different places before anything else is known.

Level decides the sharpest argument the board will force on you, and it is measured rather than estimated. Easy boards fall to the numbers alone and to the two ends of each line. Medium needs the crosses read as walls. Hard needs a filled block attached to a run. Expert needs a line where one or two filled cells adrift in the middle only make sense once the whole line is taken in at once.

The two are independent, and the difference is worth knowing before you pick. A twenty at easy is four hundred cells of steady, satisfying sweeping. A ten at expert is a hundred cells and at least one place where nothing whatsoever happens until you sit down with a single row and work out every arrangement it still allows.

Common questions

More Nonogram pages

• Daily nonogramA new picture every day
• Nonogram rulesOne rule, in full
• Solving a boardA 20×20, worked
• Nonogram techniquesThe whole ladder
• OverlapTechnique — the opening
• The ends of a lineTechnique — easy
• Gaps and splittingTechnique — medium
• GlueTechnique — hard
• The whole lineTechnique — expert
• Guessing at nonogramsTechnique — refused
• Printable nonogramsFor paper
• Nonogram archiveEvery past picture