Nonogram solving techniques
Every Nonogram on this site can be solved with the techniques below, one line at a time and without guessing. They run from the easiest to the hardest, and a puzzle's level depends on which of them it needs and how often. The hint button in the game shows these same steps.
Counting
Used in: Hard, Expert
Some lines can be finished by counting alone. A line with no clue is empty, a clue that fills the line exactly leaves no choice, and once all the filled cells, or all the empty ones, of a line are found, the rest follow.
Example
Overlap
Used in: Hard, Expert
Place a run as far to one end as the clues allow, then as far to the other end. Cells the run covers in both positions are filled, wherever it really sits. Long clues in short lines give the most.
Example
Edges
Used in: Hard, Expert
Count in from an edge of the grid. If the first cell that is not known to be empty is filled, it is the start of the run nearest that edge. Extend it to that run's full length and close it with an empty cell.
Example
Dead gaps
Used in: Hard, Expert
A stretch of open cells that is shorter than every clue in the line can't hold any run, so it is empty. And a run that is already as long as the longest clue is finished, so the cells on both sides of it are empty.
Example
Every fit
Used in: Hard, Expert
When the quick tricks run out, try every way the line's clues fit what you already know. A cell that comes out the same in all of them is certain. It takes the most counting of all.
Example