20x20 Nonogram Puzzles

How to Play Nonograms

1. Understand the clues: Numbers on the top indicate filled cells in each column. Numbers on the left indicate filled cells in each row.
2. Multiple numbers: When there are multiple numbers (like "3 1 2"), they represent separate groups of filled cells in order, with at least one empty cell between groups.
3. Cell marking: Left-click to fill a cell, click again to mark with X, and a third time to clear it.
4. Strategy: Start with rows and columns that have large numbers or many constraints. Look for overlaps where cells must be filled regardless of how you arrange the groups.
5. Use X marks: Mark cells you're certain should be empty with X to keep track of your progress.