20×20 · Grand
20×20 Nonogram puzzle
Every puzzle verified — one solution, pure logic, no guessing
Clue numbers count consecutive filled squares. Tap or drag to fill, right-click or long-press to cross. Full rules
A picture with an interior
Twenty squares on a side is where a nonogram stops being an icon and starts being a drawing: an owl with feather texture, a lighthouse with brick courses, a whale with a fin and a tail. The deductions chain longer than a 15×15 without ever needing a guess.
Finding your way around a big grid
The board keeps its clues pinned while you pan, and the corner map mirrors the whole grid: filled squares show dark, crosses show light, and the outline marks the part you are looking at. Tap anywhere on it to bring that region into view. The zoom you choose is remembered for the size, so a 20×20 you come back to opens where you left it.
Made for one long sitting
Progress saves itself as you work, on this device, with no account. Start on a lunch break, finish in the evening — the grid, the clock, and the crosses will be waiting exactly as you left them.
Common questions
- How long does a 20×20 nonogram take?
- Usually forty minutes to an hour and a half. The picture carries more detail than a 15×15, and most of the extra time goes into interior squares rather than harder logic.
- Can I play a 20×20 on a phone?
- Yes. The board pans inside its own area with the row and column clues pinned to the edges, and the corner map shows where you are — tap it to jump. Many players prefer a desktop for the grandest grids.
- Do 20×20 puzzles need guessing?
- Never. Every grid is verified to have exactly one solution, and the Logic readout on the page tells you how deep the reasoning goes before you start.