How to play nonograms

The rules

• Each number is a run of filled squares, in the same order as the numbers, from left to right or top to bottom.
• Between two runs there is at least one empty square.
• A line with clue 3 1 in 10 squares holds a run of 3, a gap, then a single square somewhere.

Method 1: Overlap

Push a run as far left as it can go, then as far right. Squares covered both times must be filled. Example: a run of 7 in a line of 10. Pushed left it covers squares 1 to 7; pushed right it covers 4 to 10. So squares 4 to 7 are filled for sure. The same works with several runs: place them all as far left as possible, then as far right, and compare each run with itself.

Method 2: Simple sums

Add the runs plus one gap between each. If the clue is 4 5 in a line of 10, that is 4 + 1 + 5 = 10, so the whole line is fixed.

Method 3: Edges

If the first square of a line is filled, the first run starts there. With clue 3 and the first square filled, squares 1 to 3 are filled and square 4 is empty.

Method 4: Mark empty squares

When a line’s runs are all placed, mark the rest with ✕. Squares out of reach of any run are empty too. These ✕ marks are just as useful as filled squares, because they limit the lines that cross them.

Method 5: Cross-check

Every square you settle in a row gives new information to its column. Go back and forth between rows and columns. Finished clues turn grey on the board so you can see which lines are done.

Colour clues

In colour nonograms each number also has a colour. Two runs of the same colour need a gap. Two runs of different colours may sit side by side. The overlap method works for each colour on its own.

Controls

• Fill or a colour button: tap or click a square to fill it. Tap again to clear it.
• ✕ Mark: mark a square as empty. With a mouse you can also right-click.
• Drag across a row or column to fill or mark many squares at once.
• Undo and Redo step back and forward (Ctrl+Z and Ctrl+Shift+Z).
• Check shows any mistakes in red. Hint makes one logical step for you.
• Keyboard: arrow keys to move, Space to fill, X to mark.

Frequently asked questions

What is a nonogram?

A nonogram is a logic puzzle where you fill squares in a grid to reveal a picture. The numbers next to each row and above each column give the lengths of the runs of filled squares in that line, in order.

Is a nonogram the same as a Japanese crossword, griddler or hanjie?

Yes. These are different names for the same kind of puzzle. Other names include paint by numbers and pic-a-pix.

Do I ever need to guess?

Not on nonogram.dev. Every puzzle here was checked with a line solver: it has one solution, and you can reach it by working on one row or column at a time.

What does a 0 clue mean?

A 0 means the whole row or column is empty. Mark every square in it with ✕.

How does the hint button work?

The hint finds one row or column where the clue, together with the squares you have already got right, proves that some squares must be filled or empty. It fills or marks those squares and tells you which line it used. If you have made a mistake, the hint shows the wrong square first.

Is my progress saved?

Yes. Your squares are saved in your browser’s local storage after every move, on this device only. There is no account.

Which size should I start with?

Start with 5×5 to learn the rules, then try 10×10. 15×15 and larger grids take longer.

How do colour nonograms work?

Each clue number has a colour. Runs of the same colour must have at least one empty square between them, but runs of different colours can touch.