Nonogram (Picross) - Free Online Picture Logic Puzzle - Free Online

About the Nonogram

Nonograms — also known as Picross, Griddlers or Hanjie — are picture logic puzzles. Each row and column carries a set of numbers listing the runs of filled squares in order: a clue of "3 1" means a block of three filled cells, a gap, then a single filled cell. By cross-referencing the row and column clues you deduce exactly which squares to fill, and a hidden picture emerges. There is no arithmetic and no guessing in a well-made nonogram — just careful logic. Choose a 5×5 to warm up or a 15×15 for a proper challenge.

How to play

Pick a size. Numbers appear beside each row and above each column.
Each clue lists the lengths of filled runs, in order, for that line.
Tap cells to fill them; switch to Mark mode (or right-click) to cross out empties.
Fill exactly the squares the clues demand to reveal the picture and win.

What it measures

This test focuses on your logical reasoning, visual working memory and patience. A 5×5 falls in a minute or two once the logic clicks; a 15×15 can take fifteen minutes or more. A no-mistake solve matters more than raw speed — it means you deduced rather than guessed.

Why play it

A pure logic puzzle that doubles as a visual, meditative challenge
Cross-referencing rows against columns is a real working-memory workout
Marking known-empty cells trains the same elimination logic as Sudoku

Did you know?

Nonograms were invented in 1987 by Japanese graphics editor Non Ishida, who won a competition designing images out of grid windows on a skyscraper.
The name "nonogram" comes from Non Ishida; in the UK the puzzles were popularised as "Griddlers" by James Dalgety.
Nintendo turned them into the Picross video-game series, which has sold across Game Boy, DS and Switch for decades.
Like Sudoku, solving a general nonogram is NP-complete — but the hand-crafted ones you play are always solvable by logic alone.

What counts as a good score?

No published norms exist for this format, so the ranges below are practical skill tiers rather than measured population data.

Level	Grid size handled	What it means
Learning	5×5 to 10×10	Working out how clue sequences constrain a line, one line at a time.
Comfortable	15×15	Using overlap reasoning to fill forced cells before any line is fully determined.
Strong	20×20	Cross-referencing rows against columns fluently and tracking multiple partial deductions.
Expert	25×25 and larger	Comfortable with sparse, ambiguous openings where nothing is forced for many moves.

Tiers describe grid sizes rather than measured solve times, since nonogram difficulty depends far more on clue structure than on dimensions.

How to improve your nonogram score

1.Start with the biggest clues

A clue larger than half the line always forces some filled cells in the middle, whatever its exact position. Free information, no deduction needed.

2.Use overlap reasoning

Slide a block to its leftmost and rightmost legal positions. Any cell filled in both is definitely filled.

3.Mark empties as hard as fills

Crossing out known-empty cells constrains neighbouring lines just as much as filling does, and beginners consistently under-use it.

4.Alternate rows and columns

Every cell you resolve in a row is new information for its column. Working one axis to exhaustion wastes half the puzzle's constraints.

5.Work the edges inward

Lines touching a border have one fewer degree of freedom, so they resolve earlier than interior ones.

Invented twice, in the same year

Nonograms were devised independently in 1987 by two people in Japan: Non Ishida, a graphics editor who won a window-art competition with grid images, and Tetsuya Nishio, a puzzler. James Dalgety coined the English name "nonogram" after Ishida when the puzzles reached The Sunday Telegraph in 1990.

The many names — Picross, Griddlers, Hanjie, Paint by Numbers — come from that split origin and from Nintendo's Mario's Picross popularising them outside Japan in 1995.

Also NP-complete

Solving general nonograms is NP-complete, proved by Ueda and Nagao in 1996. As with Minesweeper, that is a statement about worst cases: published puzzles are deliberately constructed to be solvable by line-by-line logic without search, which is exactly what makes them satisfying rather than tedious.

Frequently Asked

What is a nonogram?

A nonogram is a picture logic puzzle on a grid. Numbers beside each row and column tell you the lengths of the filled runs in that line. By combining the row and column clues you work out which cells to fill, revealing a hidden picture. It is also called Picross, Griddler or Hanjie.

How do the clues work?

Each clue is a list of run lengths in order. A row clue of "4 2" means a run of four filled cells, then at least one gap, then a run of two — reading left to right. Column clues read top to bottom. The clue order and the gaps between runs are what let you deduce the solution.

Do nonograms need guessing?

A well-formed nonogram can always be solved by logic alone — you never have to guess. Start with the lines whose clues nearly fill the whole length, mark the cells that must be empty, and cross-reference until each cell is forced.

Do nonograms always have a unique solution?

Well-constructed ones do — uniqueness is part of what makes a puzzle valid. Randomly generated grids often have several solutions, which is why quality nonogram sources verify uniqueness before publishing.

What is the difference between a nonogram and Picross?

Nothing but the name. Picross is Nintendo's branding, Hanjie and Griddlers are others. The puzzle is identical.

Nonogram (Picross) - Free Online Picture Logic Puzzle