Free online 20x20 nonogram — hard

A grid ready to play below — tap or click to fill, ✕ to mark blanks. Solvable by pure logic.

Why play hard 20x20?

The 20×20 is the nonogram marathon: 400 cells and clue runs that fill the margin. The key is staying systematic — sweep the rows, then the columns, and never guess. One grid can fill an entire evening.

On hard, the grid is sparse: every cell is earned, the back-and-forth multiplies, and the advanced techniques — overlap, edge logic — earn their keep on every line.

This page’s grid has 214 filled cells out of 400 (54%) and resolves in 8 propagation passes — verified solvable without ever guessing, like all our grids.

Keep going

• The full game110 pictures + Daily challenge
• Learn to solveinteractive beginner guide
• Step-by-step solverpaste your clues
• Printable 20x206 paper grids
5×5 hardsame difficulty10×10 hardsame difficulty15×15 hardsame difficulty20×20 easysame size20×20 mediumsame size