# What is a nonogram, exactly

> A nonogram is a grid puzzle where number clues describe runs of filled cells; read the lines right and a hidden picture appears. Here is how it works.

Canonical: https://getyournonogram.com/blog/what-is-a-nonogram
Author: Mei Tanaka
Published: 2026-07-09

---

A nonogram is a grid puzzle in which numbers along the top and side tell you, line by line, exactly which cells to fill. Solve every line correctly and a small picture appears — an animal, a boat, a teacup — drawn by nothing but your own deduction. The numbers are not hints. They are a complete description of the picture, compressed one line at a time.

That compression is the whole game. A finished nonogram is just a picture; an unsolved one is the same picture written in a stricter language. Learning to read that language takes about five minutes. Getting fluent in it is what the rest of the puzzle's difficulty is made of.

## What do the numbers actually mean?

Each number gives the length of one unbroken run of filled cells in that row or column, in order, with at least one empty cell between runs. Clues of 4, 2 mean: somewhere in this line sit four filled cells together, then a gap of at least one cell, then two filled cells together.

Take a row ten cells wide with those clues. The four-run could start at the left edge, or sit a little further in; the two-run must come after it, with the gap between them. Every legal arrangement of that row is some placement of those two runs — nothing more. The clues never lie and never leave anything out: every filled cell in the finished picture belongs to exactly one clue, and the clues appear in the same order as their runs.

Two special cases make the grammar clearer. A line whose clue is 0 stays entirely empty — you can mark the whole thing as blank at once. And a line whose runs plus their minimum gaps exactly fill the width has no freedom at all: clues of 4, 5 on a ten-cell line spend four cells, one forced gap, and five cells, so you can complete the entire line — four filled, one blank, five filled — before reading anything else.

Columns follow the same rule, read top to bottom. This is where the puzzle earns its depth: a row tells you something, the columns crossing it each tell you something, and the picture emerges wherever those two directions agree. Every mark you set in a row also lands in some column, and the other way around — each cell answers to two clues at once.

## Why does one puzzle carry so many names?

Because it was invented twice, in the same country, at almost the same time — and then renamed nearly everywhere it traveled. The rules behind nonogram, picross, griddlers, and hanjie are identical; the labels mostly record which publisher introduced the puzzle to which audience.

The origin story is quick. In 1987, Tokyo graphics editor Non Ishida won a competition for designs made from lit and unlit skyscraper windows, and saw a puzzle in the idea; the puzzle author Tetsuya Nishio arrived at the same concept independently around the same time, according to [Wikipedia's account](https://en.wikipedia.org/wiki/Nonogram). Ishida published three "Window Art Puzzles" in Japan in 1988. When the British puzzle collector James Dalgety brought her work to The Sunday Telegraph in 1990, he coined a new name for it — Non, plus diagram — as recorded in [his own puzzle-history archive](https://www.puzzlemuseum.com/griddler/gridhist.htm).

| Name | Where it comes from |
|---|---|
| Nonogram | Coined by James Dalgety in 1990, honoring inventor Non Ishida |
| Picross | Nintendo's long-running series of the same puzzle |
| Griddlers | Chosen by Sunday Telegraph readers in a 1998 naming competition |
| Hanjie | Another of the puzzle's published names |
| Paint by Numbers, Pic-a-Pix | Publishers' names for the same rules |

If you meet a grid with numbers stacked beside its rows and columns, it is this puzzle, whatever the masthead calls it.

## What is a nonogram not?

It is not arithmetic. The numbers count cells; they are never added, multiplied, or balanced against each other. People who "aren't math people" lose nothing here — the skill is careful reading, closer to proofreading than to calculation.

It is not a word puzzle either. The grid wears a crossword's furniture — clues stacked beside rows and columns where a crossword's definitions would sit — which is how it keeps getting filed next to them, but no vocabulary is involved anywhere. The resemblance ends at the layout.

Most importantly, it is not a guessing game — or should never have to be. Hold every puzzle to this bar: one intended solution, reachable by deduction alone. Every grid in our own collections is built to it, and a grid that fails it belongs to a badly made book, not to you. The most common beginner mistake is abandoning that guarantee halfway through: the picture starts to look like a cat, so the ear gets filled in where an ear ought to go. The clues outrank the picture, always. The image is the reward for the logic, not a substitute for it.

## Where do you go from here?

Start small and let the grammar settle. A 5×5 grid teaches what the clues mean; a 10×10 starts teaching what they imply. Size is the gentlest difficulty dial the puzzle has, and there is no prize for skipping ahead. Colored variants exist as well, with an extra reading rule of their own, but the plain black-and-white grid is the right place to learn the language first.

After that, the craft is reading lines well — and that deserves its own patient treatment. The [line-by-line method](/blog/the-line-by-line-method-slowly-explained) walks through it slowly: reading one row or column at a time, marking only what cannot be wrong, and letting certainty accumulate until the picture has no choice but to appear.

A nonogram, exactly, is that promise in grid form: a picture you can be certain of before you can see it.