Nonograms

How to play

A nonogram is a picture puzzle. The grid starts empty, and the numbers beside each row and above each column tell you which squares to fill in. When every square is right, a small picture appears.

1. Read a number as a run. A clue of 3 means three filled squares side by side, with no gap, somewhere in that row or column.
2. Several numbers mean several runs, in the order shown, from left to right along a row or from top to bottom down a column. There is at least one empty square between two runs. A clue of 2 1 means a run of two, then a gap, then a single filled square.
3. Choose what a tap does with the three buttons above the grid. Fill is chosen when the page opens: tap a square to fill it, and tap it again to empty it. Mark X puts a cross in a square you know is empty, which only helps you keep track and never counts as filled. Erase empties any square you tap.
4. Watch the numbers. When the filled squares in a row or column match its clue, that clue is crossed out, and the line under the grid counts how many rows and columns match. When all of them match, the puzzle is solved and the page names the picture.

If you like to paint, tick Drag to paint, then press on a square and drag across others: each one gets the same change as the first. On a phone, dragging on the grid then paints instead of scrolling the page, so untick the box when you want to scroll. With a keyboard, move around the grid with the arrow keys and press Enter or Space to do what the chosen button says.

Worked example

Here is a small puzzle with its clues and its finished picture. Follow the reasoning, and you will see that no guessing is ever needed.

1. Rows 2 and 3 both say 5, and five squares fill a row of five. Choose Fill and tap all ten squares.
2. Column 1 says 2, and rows 2 and 3 already give it two. The rest of that column must be empty, and so must the rest of column 5, which also says 2. Choose Mark X and cross out those squares.
3. Row 1 says 1 1. Its first and last squares are empty, so the two single squares must fit among columns 2, 3 and 4 with a gap between them. That means columns 2 and 4.
4. Columns 2 and 4 say 4, and each already has filled squares in rows 1, 2 and 3. A run of 4 that includes row 1 must be rows 1 to 4, so fill row 4 in both columns.
5. Column 3 says 4, but its top square is empty, so the run is rows 2 to 5. Fill rows 4 and 5 in that column. Row 4 now reads 3 and row 5 reads 1, as their clues say, and the picture is a heart.

Daily puzzle and sizes

Each size has its own daily puzzle, which changes at midnight where you are. When you have finished, press Next puzzle for another, as many times as you like. A puzzle you have started is remembered in this browser, so you can come back to it.

• Small, 5 × 5: a quick puzzle with short clues, good for learning how nonograms work.
• Larger, 10 × 10: a longer puzzle with a more detailed picture. Thicker lines after every fifth square help you keep your place.

Every puzzle can be solved by reasoning alone, working row by row and column by column, and has exactly one answer.

Tips

• Start with the biggest numbers. A clue that is nearly as long as the line, such as 8 in a row of 10, always fills the squares in the middle.
• Add up the numbers in a clue and one gap for each space between them. If the total equals the length of the line, the whole line is decided.
• Use Mark X freely. Knowing a square is empty is just as useful as knowing it is filled.
• Jump between rows and columns. Each square you settle gives another line a little more to work with.
• If the numbers feel small, choose Text size and colours at the top of the page.
• Stuck? Show answers shows the finished picture, and Print with answers puts it on a second page.

How these puzzles are made

Each picture is designed square by square for this site, and none are made at random. A program turns the picture into its clues. Before a puzzle appears, the program solves it the way you would, one row or column at a time and never by guessing. If it cannot finish that way, the picture is not used, so a puzzle you are shown always has exactly one answer that logic can find. Whether you have solved it is decided by the clues, not by comparing with a stored picture. Automated tests repeat these checks on every picture whenever the puzzle code or the pictures change.