How to play Nonogram
Nonogram is a picture-logic puzzle. Every row and column has a clue: the lengths of the runs of filled squares in that line, in order. Work out which squares to ink so that every clue is true at once.
Each puzzle here is generated fresh, has exactly one solution and can be finished by pure line-by-line logic — you never need to guess.
Rules
- A clue such as “3 1” means the line holds a run of three filled squares, then at least one gap, then a single filled square. A “0” means the whole line is empty.
- Runs keep the order of the clue, and there is always at least one empty square between two runs.
- Cross out squares you know are empty. Crosses are notes for you: they never count against you and are not needed to finish.
- A clue turns grey as soon as the inked squares in its line match it exactly.
- The puzzle is solved the moment your inked squares match every clue; the clock stops and the picture is left on the paper.
- Check briefly marks wrong squares in red and Hint fixes one square. Either one keeps that solve off your best time and the leaderboard.
- Choose 5 × 5, 10 × 10 or 15 × 15. Each size keeps its own puzzle in progress, so you can switch and come back.
Controls
- Click / tap
- Fill a square (or cross it out in Cross mode); again to clear
- Drag
- Paint a straight line along the row or column you started in
- Right-click / long-press
- Cross out (the other tool)
- M
- Switch the click tool between Fill and Cross
- Arrows / WASD
- Move the keyboard cursor
- Space / Enter / F
- Fill or clear the square under the cursor
- X
- Cross out or clear the square under the cursor
- Shift + arrows
- Carry the current square’s mark along as you move
- Backspace
- Clear the square
- Z / Ctrl+Z
- Undo
- C / H
- Check / Hint
- P
- Pause
Tips
- Start with big clues. In a 10-square line, a run of 7 must cover the middle four squares wherever it sits — ink them straight away.
- Add up a clue plus its gaps: “4 3 1” needs 4 + 3 + 1 + 2 = 10 squares, so in a 10-square line it fits exactly and solves the whole line at once.
- Cross out generously. Once a run is complete, the squares at both ends must be empty, and crosses there unlock the neighbouring lines.
- Use the hover highlight to keep your place on big boards, and the heavier rule every fifth line to count quickly.
Nonogram strategy
Overlap with several clues
The middle-overlap trick works for whole clues, not just one big run. Push every run as far left as it goes, then as far right, keeping single gaps. Any run that covers the same squares in both positions inks them. In a 15-square line, “6 5” needs 12 squares, leaving 3 spare. So the 6 inks its middle three and the 5 its middle two, before you know anything else about the line.
Anchor runs to walls
A filled square near an edge often belongs to the first run. If the first clue is 4 and the third square from the wall is inked, no earlier run exists, so that run covers it and reaches at least the fourth square. Ink squares three and four straight away. A crossed-out square works exactly like a wall, so every cross you place creates new edges to anchor against.
Cross the gaps no run fits
After a few moves, lines break into pockets between walls and crosses. If a pocket is shorter than every run that could still go there, cross it out. Likewise, once the runs that can reach a stretch are all placed elsewhere, the stretch is empty. When a clue turns grey and you trust its inks, every other square in that line is empty, so cross out the rest.
Follow the changes
Every puzzle here can be finished one line at a time, so you never need to hold the whole picture in your head. After you change a row, check only the columns you touched, then the rows those columns touch. On 15 × 15 this rhythm beats sweeping the whole board. Keep Check and Hint for genuine dead ends: either one keeps that solve off your best time.
About Nonogram
Nonograms were invented independently in Japan in 1987 by the graphic editor Non Ishida, who designed pictures from lit skyscraper windows, and the puzzle setter Tetsuya Nishio. The British puzzler James Dalgety named them “nonograms” after Ishida and they ran in The Sunday Telegraph from 1990, before spreading to puzzle magazines and handheld consoles around the world under many names: griddlers, paint by numbers, hanjie.
Our puzzles are random patterns rather than drawings: each one is generated at about 55% ink and kept only if a line-by-line solver can finish it, which proves the solution is unique and reachable without guessing.
Questions
Do I ever have to guess?
No. Every puzzle is checked by a solver that only uses line-by-line logic, and only kept if that solver finishes it. If you are stuck, there is a deduction somewhere in a single row or column.
Do I need to cross out every empty square?
No. Crosses are only notes. The puzzle is solved as soon as the filled squares match every clue.
What do Check and Hint do to my time?
Check briefly marks squares that are wrong and Hint fixes one. The clock keeps running, and a solve that used either is recorded in your history but does not count for your best time or the leaderboard.
Is my puzzle saved if I leave?
Yes. Progress is saved in your browser separately for each size, and the clock pauses while the tab is hidden.