Nonogram

Picture logic puzzle — fill the grid from the row and column number clues to reveal a hidden picture. Three sizes, ranked scores.

How to play Nonogram (picture logic puzzle)

A nonogram — also called a picture cross, griddler or Hanjie — is a logic puzzle in which numbers along the edges of a grid describe a hidden picture. Each row and each column carries a sequence of clue numbers that tell you the lengths of the filled runs in that line, listed in order. By combining what the row clues and the column clues demand, you can deduce, square by square, exactly which cells are filled and which are blank. Solve the whole grid and a small picture appears. Every puzzle here has one and only one solution, so you never have to guess.

The goal

Fill in the correct cells of the grid so that every row and every column exactly matches its clue numbers. When all the filled cells are in place — no more and no fewer — the hidden picture is revealed and the puzzle is solved. You are timed, and filling a cell that should have stayed blank counts as a mistake, so accuracy matters as much as speed.

The grid and the clues

The board is a square grid — 5×5, 10×10 or 15×15 depending on the difficulty you pick. Numbers run down the top of every column and across the left of every row. Each number is the length of one unbroken run of filled cells, and the numbers are listed in the same order those runs appear along the line. Where a line has several runs there is at least one blank cell between them. A line with a single 0 clue is completely blank. As you correctly complete a line, its clue can dim so you can track your progress at a glance.

Rules

Each clue number is the length of a block of consecutive filled cells in that row or column.
When a line has more than one number, the blocks appear in the given order — left to right for rows, top to bottom for columns — with at least one blank cell between neighbouring blocks.
A clue of 0 (an empty clue) means the whole line stays blank.
A cell is either filled or blank in the finished picture. Marking a cell with an X is just a personal note that it is blank — X marks never count toward the solution.
The puzzle is solved when the filled cells match every row clue and every column clue at the same time. There is always exactly one arrangement that does this.

Reading the clues

Read each clue as a recipe for its line. The clue “5” on a length-5 line means the whole line is filled. The clue “3 1” on a length-8 row means: somewhere from the left there is a run of three filled cells, then at least one blank, then a single filled cell, and any remaining cells are blank. The order is fixed but the exact starting positions are not — that is what you work out. Because a row clue and a column clue both pass through the same square, the two constraints together often pin a cell down even when neither could on its own. Cross-referencing rows against columns is the heart of the puzzle.

Solving techniques

Overlap. When a block is long compared with the space it can occupy, its leftmost and rightmost possible positions overlap in the middle. Those overlapping cells must be filled wherever the block finally sits. On a length-5 line, a clue of 4 always fills the middle three cells.
Edges. A block that touches the end of a line is anchored: if a row starts with a filled cell and its first clue is 3, the first three cells are filled and the fourth must be blank. Use any known filled or blank cell near an edge to extend the deduction inward.
Completing and closing. Once a line’s blocks are all placed, mark every remaining cell in that line blank with an X. Those X marks feed straight into the crossing lines and often unlock them.
Cross-referencing. Fill or cross out a cell using a row clue, then switch to the column through that cell and see what the new information forces. Alternate between rows and columns; each pass usually reveals a little more.
Never guess. Every puzzle has a unique solution reachable by pure logic. If you are stuck, look for the line with the most filled or blank cells already known — it usually has a forced move waiting.

Controls

Left-click or tap a cell to fill it; click a filled cell again to clear it. Right-click, or press and hold on a touch screen, to place an X on a cell you have worked out is blank; do it again to remove the mark. The X marks are only there to help you keep track — you can win with or without them. Use New Puzzle to generate a fresh grid at any time, and the size selector to switch between the 5×5, 10×10 and 15×15 boards.

Scoring and the leaderboard

Your score is calculated the moment you complete the picture: score = cells + 8000 − seconds − mistakes × 300, where cells is the number of squares in the grid (25, 100 or 225). A larger grid starts you higher, but every second and every wrong fill trims the total. The best possible score comes from a fast, mistake-free solve. Scores are capped between 1 and 99,999 and recorded per difficulty, so each board size has its own leaderboard.

Frequently asked questions

Does every nonogram have exactly one solution?

Yes. The generator draws a random picture, works out its clues, then runs a full logic solver that counts how many grids those clues allow. It only accepts a picture whose clues have a single unique solution; anything ambiguous is thrown away and a new picture is tried. Because of that check you can always reach the answer by reasoning alone — you never have to guess.

What should I do when I get stuck?

Slow down and hunt for a forced move rather than guessing. Look for long blocks that create overlaps, lines that are nearly finished, and cells where a row clue and a column clue combine. Marking blank cells with an X often reveals the next filled cell in the crossing line. There is always a logical next step somewhere on the board.

Do the X marks affect whether I win?

No. An X mark is a solving aid that means “this cell is blank.” Winning is decided only by the filled cells: when the set of filled cells exactly matches the hidden picture, the puzzle is solved, whether or not you marked the blanks. Some solvers X every blank cell as they go; others fill only and leave the blanks empty. Both styles work.

How is my score worked out?

score = cells + 8000 − seconds − mistakes × 300. Cells is 25 on the 5×5 board, 100 on the 10×10 and 225 on the 15×15. A mistake — filling a cell that should have stayed blank — costs 300 points, and every second costs one point, so quick, clean solving scores best. The result is clamped to the 1–99,999 range and stored separately for each board size.

Which grid size should I start with?

Start on the 5×5 (Easy) board to learn how the clues read and how overlaps work. Move up to 10×10 (Medium) once the basic deductions feel natural, and take on 15×15 (Hard) for a full-length picture that rewards careful cross-referencing. Each size keeps its own best score, so there is always a new personal record to chase.

Can I play offline?

Yes. Once the page has loaded, everything — generating a fresh, uniquely solvable puzzle, checking your fills and keeping the timer — runs entirely in your browser with no internet connection. Ranked scores earned offline are stored on your device and upload automatically the next time you are online and signed in.