Line Completion: Step-by-Step Guide

When the total filled cells described by a clue string exactly fit the remaining spaces, you can paint the entire run immediately. It’s the quickest way to reveal chunks of the picture.

Prerequisites

None. This is the first technique to master.

How to recognize it

  • Total length match: Sum of clue numbers plus required gaps equals the line length.
  • Heavy overlap: Large clues overlap when counting from both ends, forcing shared filled cells.
  • Edge hugging: A clue nearly as long as the row must start at the edge, revealing an entire block.

Why it works

Nonogram clues define the exact count and order of filled cells. If there is only one way to place that pattern within the open space, every cell in the run becomes a guaranteed paint.

Try it now

Interactive example coming soon: watch the overlap bar reveal forced tiles, then tap to fill them in.

Practice puzzles

We will link daily puzzles that emphasize quick line completions here.

Common pitfalls

  • Forgetting the mandatory one-cell gaps between clue groups, leading to extra fills.
  • Missing overlap opportunities by not counting from both ends of the line.

Related: Confident Marking