Nonogram: How to Solve Picross Puzzles 🖼️
Published: August 10, 2026 · 6 min read
Nonograms — also called Picross, Griddlers or Hanjie — are the friendliest way into logic puzzles, because the reward is visual. You are not filling in digits; you are developing a photograph one deduction at a time.
The rules
Numbers run along the top and the left of the grid. They describe the runs of filled cells in that column or row, in order, with at least one blank between consecutive runs.
A row clue of 4 2 in a 10-wide grid means: a block of four filled cells, then at least one blank, then a block of two. Your job is to work out where.
The overlap technique
This is the one that lets you start any board without guessing, and it's worth understanding properly.
Take a row of 10 with the single clue 7. Slide that block of seven as far left as it goes: it covers cells 1–7. Slide it as far right: it covers cells 4–10. Every position it could possibly occupy includes cells 4, 5, 6 and 7 — so those four are filled, no matter what.
The rule generalises: overlap = run length − (line length − sum of all clues and mandatory gaps). In practice you don't compute it, you just imagine the block pushed to each end and fill whatever both positions share. Any clue larger than half the line gives you something.
Edge forcing and completion
Edge forcing. If the first cell of a row is filled and the first clue is 3, then cells 1, 2 and 3 are filled and cell 4 is definitely blank. Anchoring at an edge removes all the ambiguity from that clue.
Completion. Once a line's runs are all placed, every remaining cell in it is blank — mark them. Marking blanks is not busywork; those crosses are what let the perpendicular lines resolve. Players who only fill cells and never mark blanks stall constantly.
Alternate directions. Work a row, then work the columns it just constrained, then come back. A nonogram unlocks in waves, and staying in one direction wastes them.
About our version
99 levels growing from 5×5 to larger grids, each one an actual recognisable picture rather than noise. Tap to fill, long-press or switch mode to mark a blank. Unlimited undo, hints, and a solver-verified single solution on every board.
It runs in your browser, works offline once loaded, needs no account, and costs nothing.
Questions people actually ask
What's the difference between a nonogram and Picross?
Nothing — they're the same puzzle. Picross is Nintendo's name for it, and Griddlers and Hanjie are two more. We call ours Nonogram.
Do nonograms require guessing?
Well-made ones don't. Every board here has a single solution reachable by logic; if you're stuck, there's a line where the overlap or a completed perpendicular gives you the next cell.
Why should I mark the blank cells?
Because the crosses are what let crossing lines resolve. A cell you know is empty is exactly as informative as a cell you know is filled, and skipping them is the most common reason people stall.
Keep reading
- Patch: Shikaku, the Rectangle-Cutting Puzzle ▭ — Divide the grid into rectangles, each containing one number equal to its area. Primes are your best friends here — and they tell you exactly where to start.
- Logic Puzzle Games: A Guide to the 12 in Go Brain 🧠 — Sudoku, Kakuro, Nonogram, Crowns and eight more. What separates a real deduction puzzle from a guessing game, and which to start with.
- Minesweeper Without the Coin Flips 💣 — Everyone has lost a Minesweeper game to a coin flip. Ours generates boards that can always be cleared by reasoning — plus the two patterns worth memorising.
Play Nonogram now
99 picture puzzles, undo and hints, verified single solutions. Free, no account.