The rules page says what the numbers mean. This one says what to do first.
Start with the longest clues
Take a line whose clue is more than half its length. Push that run as far left as it goes, then as far right; wherever it covers a square both times, that square is filled no matter how the run finally sits.
That single idea carries a large share of the work. Across this site's 175 pictures it settles two steps in five, and together with finishing a line it covers 98 of every 100, so it is worth reaching for before anything else.
Then cross off, before you fill anything more
When a line already holds every run its clue asks for, all its other squares are empty. Marking them costs nothing and narrows every line that crosses them.
Beginners tend to hunt for the next square to fill. The next square to cross off is usually easier to find and does more work.
The crossings hand you the next move
A nonogram is solved by going back and forth: a row settles part of a column, that column settles part of another row. If a line stops giving you anything, leave it and come back after its neighbours have moved.
Nothing here ever needs a guess. If you cannot find the next square, there is one to be found — that is what being checked before publication means.
If you get stuck, the hint names the rule
Asking for a hint does not just open a square. It tells you which rule applies and lights up the line it read, so the next one of those you can find yourself.
There are six rules in all, and two of them cover most of a puzzle. The rest only turn up when a grid gets tight.
Techniques
| Rule | Share of steps |
|---|---|
| Line finished Every block in this line is already placed, so what is left must be empty — or the other way round. | 55% |
| Overlap Push the blocks as far left as they go, then as far right; wherever a block lands both times, it is filled. | 42.8% |
| Block finished This run of filled squares is already as long as any block that could sit here, so both ends are empty. | 1.2% |
| Gap too small This gap is shorter than the smallest block left, so nothing fits and all of it is empty. | 0.3% |
| Out of reach No block can stretch this far, wherever it starts, so this square is empty. | 0.7% |
| Compare every arrangement None of the shorter rules apply, so every legal arrangement of this line is compared and the squares they agree on are settled. | — |