Explainer
What Is a Nonogram? Picross, Griddlers and Hanjie Explained
One puzzle, half a dozen names. Here's what a nonogram actually is, how it differs from sudoku, and the short history of how a Tokyo graphic editor's idea ended up on Nintendo consoles.
Definition: a nonogram is a picture logic puzzle. You get an empty grid with numbers beside each row and column; each number is the length of a run of filled cells in that line. Using only those clues, you work out which cells to fill, and when you're done the filled cells form a picture. Nonograms are also called picross, griddlers, hanjie, paint by numbers, pic-a-pix and Japanese crosswords.
On this page
How a nonogram works
Here is a tiny finished one. The clue 1 1 on the top row means “one filled cell, a gap, then one more filled cell.” The 5 on the next row means all five cells are filled. Every clue in the grid agrees with the picture, and the picture is the only one that fits all the clues at once.
The appeal is that the puzzle is pure deduction. A well-made nonogram has exactly one solution, and you can always find the next cell by reasoning rather than guessing. Small ones take a minute or two; giant 50×50 grids can take an evening. If you want to try one, our beginner's guide solves this exact puzzle step by step.
Why does it have so many names?
Nonograms spread through newspapers, puzzle magazines and video games in different countries at about the same time, and each publisher picked its own name. The puzzle under each name is the same.
| Name | Where it comes from |
|---|---|
| Nonogram | Coined by British puzzle collector James Dalgety from inventor Non Ishida's first name plus “diagram.” The most common neutral name. |
| Picross | Nintendo's trademark, short for “picture crossword.” Used on Mario's Picross, Picross DS, Picross 3D and the Picross e and Picross S series. |
| Griddlers | The name readers chose in a 1998 Sunday Telegraph competition. Common in the UK and on griddlers.net. |
| Hanjie | A name used by many UK newspapers and puzzle books. |
| Paint by numbers / Pic-a-Pix | Puzzle-magazine names that emphasise the picture you reveal. |
| Japanese crossword | A nod to the puzzle's origin, common in Eastern Europe and in app titles. |
So if you're asking “picross vs nonogram,” there's no difference in the rules. “Picross” usually just means you're playing one of Nintendo's games or something inspired by them.
A short history of nonograms
- 1987: Tokyo graphic editor Non Ishida wins a competition with a picture made by switching skyscraper lights on and off in a grid, and develops the idea into a puzzle. Around the same time, professional puzzle maker Tetsuya Nishio independently invents the same kind of puzzle.
- 1988: Ishida publishes three puzzles in Japan as “Window Art Puzzles.”
- 1990: Through James Dalgety, the British newspaper The Sunday Telegraph starts running them weekly under the name “nonograms.”
- 1995: Nintendo releases Mario's Picross for the Game Boy in Japan, starting the long-running Picross brand.
- 1998: The Sunday Telegraph renames its puzzles Griddlers after a reader competition.
- 2009–2010: Picross 3D on the Nintendo DS turns the grid into a block of cubes, inventing the 3D nonogram as most people know it.
- 2010s to today: Picross e on the 3DS, Picross S on the Switch and hundreds of mobile apps keep nonograms among the most popular logic puzzles around. See our pick of the best nonogram apps for iPhone.
Nonograms vs sudoku
People who like sudoku tend to like nonograms, and vice versa. Both are pure-logic puzzles with a unique solution, but they feel different to solve.
| Nonogram | Sudoku | |
|---|---|---|
| Goal | Fill cells to reveal a picture | Place digits 1–9 |
| Clues | Run lengths beside every row and column | Some digits already in the grid |
| Grid size | Anything from 5×5 to 100×100+ | Almost always 9×9 |
| Reward | A picture appears as you solve | A completed grid |
| Core skill | Reasoning about where runs can fit | Reasoning about which digits are missing |
Variants: colour and 3D
Colour nonograms use clues in several colours. Runs of different colours don't need a gap between them, which changes the logic in interesting ways.
3D nonograms go a step further. You start with a solid block of cubes, and each clue on a cube face counts how many cubes in that line belong to a hidden shape, with a marker for whether they form one, two, or three-or-more groups. You chip away everything that doesn't belong until a small sculpture is left. It's the same deduction in an extra dimension, and every cube is crossed by three lines instead of two.
That's the idea behind Carve, our 3D nonogram game for iPhone: 200 handcrafted puzzles, each one ending with a voxel sculpture (a cat, a torii gate, an elephant) that you carved yourself.
Frequently asked questions
Is picross the same as a nonogram?
Yes. Picross is Nintendo's name for nonograms, short for “picture crossword.” The rules are identical; Picross is simply the brand used on Nintendo's games, such as Mario's Picross, Picross DS and the Picross S series.
Why is it called a nonogram?
The name was coined by British puzzle collector James Dalgety, combining “Non,” from inventor Non Ishida's name, with “gram,” from “diagram.”
Who invented nonograms?
Japanese graphic editor Non Ishida devised the idea in 1987, and professional puzzle maker Tetsuya Nishio independently invented the same kind of puzzle around the same time.
Is a nonogram a math puzzle?
Not really. You only need to count small numbers; the challenge is logical deduction. Computer scientists have shown that solving nonograms in general is NP-complete, which is part of why big ones feel so satisfying.
What is a 3D nonogram?
A 3D nonogram moves the clues onto the faces of a solid block of cubes. Instead of filling in a flat picture, you remove the cubes that don't belong until a small sculpture is left. Picross 3D on the Nintendo DS popularised the format, and Carve brings it to iPhone.