Nonogram (Picross)

Nonogram, also known as Picross, Griddler, or Paint by Numbers, is a logic puzzle where you fill cells in a grid to reveal a hidden picture. Each row and column has number clues that tell you how many consecutive filled cells appear in that line and in what groupings. By cross-referencing row and column clues, you can logically deduce which cells should be filled and which should remain empty. Nonograms originated in Japan in the late 1980s and were independently created by Non Ishida and Tetsuya Nishio. The puzzle gained worldwide popularity through newspaper publications and Nintendo's Picross game series. Today, nonograms are enjoyed by millions of logic puzzle enthusiasts who appreciate the satisfying reveal of a hidden image through pure deduction.

1. Each row and column has number clues. These numbers indicate groups of consecutive filled cells in that line.
2. For example, a clue of '3 1' means there is a group of 3 filled cells, at least one empty cell, then a group of 1 filled cell.
3. Use logic to determine which cells must be filled based on the clues for both the row and column.
4. Mark cells you are certain should be empty with an X to help you track your progress.
5. Cross-reference row and column clues to narrow down possibilities. A cell that must be filled according to both its row and column clues is a certain fill.
6. Complete the grid by filling all correct cells to reveal the hidden picture.

• Number clues show the lengths of consecutive filled cell groups in order from left to right (rows) or top to bottom (columns)
• Groups must appear in the order shown and must have at least one empty cell between them
• A clue of '0' means the entire line is empty
• Every cell is either filled or empty, and every clue must be satisfied exactly
• The puzzle has exactly one valid solution
• No guessing is needed for a properly constructed nonogram

• Start with the largest clues. A row clue that nearly fills the entire row gives you the most information. For example, a clue of '8' in a 10-cell row means at least the middle 6 cells must be filled.
• Look for lines where the total of all clue numbers plus minimum gaps equals the line length. These lines can be completely filled in immediately.
• Use the overlap technique. If a group of N cells can start at position A or position B, any cells that overlap in both positions must be filled.
• Mark confirmed empty cells with X marks. This is just as important as filling cells because it constrains future deductions.
• Re-examine completed or nearly completed lines. When a line has most cells determined, the remaining cells often become obvious.
• Work back and forth between rows and columns. Information from solving one direction feeds into solving the other.

• Standard Nonogram (Black and White): The classic version with a single color. Fill or leave empty. The most common format for beginners and experts.
• Color Nonogram: Uses multiple colors with separate clues for each. Same-color groups need gaps between them, but different colors can be adjacent.
• Mega Nonogram: Very large grids (25x25 or larger) that create detailed pictures. These puzzles take longer but produce impressive results.

• The satisfying reveal of a hidden picture through pure logic
• Scalable difficulty from tiny 5x5 grids to massive 25x25 puzzles
• No math required, just logical deduction and pattern recognition
• Deeply relaxing yet mentally stimulating gameplay
• Every puzzle produces a unique picture as a reward for solving it

Play Nonogram puzzles for free in your browser. Choose from 5x5, 10x10, and 15x15 grid sizes. Features include fill and mark modes, clue completion tracking, and timer. No download needed. Works on all devices.

Nonogram puzzles offer one of the most rewarding logic puzzle experiences available. The combination of deductive reasoning and the visual payoff of revealing a hidden picture makes every puzzle feel like an accomplishment. Pick a grid size and start solving now.