If you've ever stared at a grid full of numbers and wondered how anyone turns it into a picture, you're in the right place. Learning how to solve nonograms looks intimidating at first, but the entire puzzle runs on a handful of simple logic rules. Once they click, you'll never need to guess again.
This guide walks you through everything from zero: what the numbers mean, the core techniques that solve any grid, and a full step-by-step example you can follow along with. No prior experience needed.
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What is a nonogram? (Picross, griddlers, and other names)
A nonogram is a logic puzzle played on a grid. Each row and column has a set of numbers, and those numbers tell you which squares to fill in. When you fill the correct squares, a hidden picture appears.
You may have seen the same puzzle under different names — they're all identical in how they work:
- Picross (the popular Nintendo name)
- Griddlers
- Hanjie
- Picture cross or picture logic
- Japanese crosswords
The rules never change. Learning how to play Picross is exactly the same as learning how to play a nonogram.
How nonogram clues work
Every number is a clue about one line (a single row or column). The number tells you how many squares in a row must be filled consecutively, with no gaps inside that block.
- A clue of
5means five filled squares in a row. - A clue of
3 2means a block of three filled squares, then at least one empty square, then a block of two filled squares — in that order, left to right (or top to bottom).
The 3 golden rules of solving nonograms
Before any technique, keep these in mind:
Only use logic — never guess
A well-made nonogram always has exactly one solution you can reach by reasoning. If you're guessing, you're missing a deduction.
Mark empty squares too
Filling squares is only half the job. Marking squares you know are empty (usually with an ✕) is just as powerful, because it narrows down where blocks can go.
Work rows and columns together
Every square belongs to both a row and a column. A clue you can't crack from the row often becomes obvious from the column.
Beginner techniques to solve any nonogram
These four moves alone will get you through the vast majority of easy and medium puzzles.
1. Start with full lines
Look for any line where the clue fills the entire length. In a 10-wide grid, a row clue of 10 means every square is filled. A clue of 4 5 in a 10-wide row also fills everything (4 + 1 gap + 5 = 10).
These "free" lines cost you no thinking and immediately give you filled squares that help crack the crossing lines. Always do these first.
2. Use the overlap technique (the most important trick)
This is the single most useful nonogram tip for beginners. When a clue is large relative to the line, some squares must be filled no matter where the block ends up.
Here's the easy way to find them:
- Imagine sliding the block as far to the left as it will go.
- Now imagine sliding it as far to the right as it will go.
- Any square that's filled in both positions is guaranteed to be filled.
A 5-wide row with a clue of 4. Squares 2, 3 and 4 are covered in both positions — fill them immediately, even before you know where the block actually sits.
The bigger the number compared to the line, the more squares this reveals.
3. Mark the empty squares
Whenever you complete a block, mark the squares around it that must be empty. If a row's clue is 3 and you've found all three filled squares, every other square in that row gets an ✕. Those ✕ marks then act like walls for the crossing columns, forcing new deductions.
4. Complete and close off blocks
When a filled block reaches the size of its clue, it's finished — cap both ends with an ✕. For example, if a clue is 2 and you have two filled squares touching, no square next to them can be filled, so mark those neighbors empty. This "closing off" constantly opens up the rest of the grid.
Intermediate nonogram solving techniques
Once the basics feel natural, these Picross techniques handle tougher grids.
Cross-reference rows and columns
The real engine of nonogram solving is bouncing between directions. Fill what you can in the rows, then switch to columns and use those new filled and empty squares to deduce more. Then switch back. Most of a hard puzzle is solved in this back-and-forth, not in any single clever move.
Work from the biggest numbers first
Large clues are the most constrained, so they leak the most information. A clue that's more than half the line length always forces at least one square via the overlap technique. Hunt down your biggest numbers early — they're where the guaranteed squares hide.
Use the edges to force cells
Clues near the start or end of a line have less room to move. If the first clue in a row is 3 and square 1 turns out to be empty, that whole block shifts and you can often place it exactly. Edges and corners are frequently the easiest place to break a stuck puzzle open.
A worked example: solving a 5×5 nonogram step by step
Let's solve a real one together. Filled squares are shown in moonlight blue, confirmed-empty squares get an ✕, and the squares that change at each step are ringed in coral.
Our puzzle. Row clues sit on the left, column clues on top.
Step 1 — Full lines
Rows 2 and 3 have a clue of 5 in a 5-wide grid, so fill them completely. Column 3 has a clue of 5, so fill it completely too. Three lines solved before we've done any real thinking.
The free lines: rows 2 and 3, and column 3.
Step 2 — Overlap on the columns
Columns 2 and 4 both have a clue of 4. In a 5-tall column, a block of 4 overlaps in the middle three squares (rows 2, 3, 4). Rows 2 and 3 are already filled, so this forces row 4 in both columns to be filled.
Row 4 now has three filled squares in the middle, and its clue was 3 — that block is complete. Cap the ends: mark row 4, columns 1 and 5 as empty.
Overlap fills row 4, and completing the block closes off both ends.
Step 3 — The lonely single
Row 5's clue is 1, and column 3 is already fully filled, so that one square is the entire clue. Mark the rest of row 5 empty.
One square satisfies the whole clue — everything else in row 5 must be empty.
Step 4 — Close off the side columns
Columns 1 and 5 each have a clue of 2. In both, rows 2 and 3 are filled (that's your block of 2) while rows 4 and 5 are now empty. The block is complete, so mark row 1 empty in columns 1 and 5.
A finished block of 2 in each side column forces the corners empty.
Step 5 — Finish the top
Row 1's clue is 3. Columns 1 and 5 are now empty, leaving only columns 2, 3, and 4 — exactly three squares. Fill them all.
Solved. A little gem — found with pure logic, no guessing.
Every technique above appeared here: full lines, overlap, closing off blocks, and cross-referencing. That's the whole game, and it scales all the way up to a 25×25 grid.
Common nonogram mistakes to avoid
- Guessing when stuck. There's always a logical next step. Re-scan your biggest clues and your ✕ marks instead of taking a shot in the dark — one wrong fill can quietly break the whole grid.
- Forgetting the gap rule. Separate numbers always have at least one empty square between them.
2 2in a 4-wide line is fully determined for this reason. - Skipping empty marks. If you only ever fill squares, you're solving with one hand tied behind your back. Mark what's empty.
- Ignoring one direction. Getting stuck on rows? Switch to columns. The answer is almost always waiting in the other direction.
Tips to solve nonograms faster
- Do all the "free" full lines first, then attack the largest remaining numbers.
- Solve in pencil-mode: mark empties aggressively so blocks reveal themselves.
- Zoom in on a corner and fully resolve it before moving on — solved regions cascade outward.
- Take short breaks on big grids. A fresh look often spots the deduction you were missing.
Speed comes from pattern recognition, and pattern recognition comes from volume. The more puzzles you solve, the faster the overlaps and closures jump out at you.
What about color nonograms?
Classic nonograms are black-and-white: a square is either filled or empty. Color nonograms add a twist — clues can specify different colors, and the whole grid resolves into a full-color picture instead of a silhouette.
That small change adds a satisfying new layer of deduction and lets the finished puzzles look genuinely beautiful.
Practice on a calm color grid
Hueku is a color-nonogram game built exactly for this — precise controls, soft lamp-lit design, and hundreds of picture puzzles to work through at your own pace. Every puzzle is verified to be solvable by logic alone. It's a good way to turn these techniques into muscle memory.
Get Hueku on the App Store → 🌙 out now on iPhone & iPad — free to playFrequently asked questions
What's the difference between Picross and nonograms?
There is no difference in gameplay. "Picross" is the brand name popularized by Nintendo, while "nonogram" is the generic term. Griddlers, Hanjie, and picture cross are other names for the same puzzle.
Are nonograms good for your brain?
They're excellent for logical reasoning, pattern recognition, and focus. Because solving relies entirely on deduction rather than luck, nonograms give your brain a steady, rewarding workout — a big part of why they're such a popular way to relax and stay sharp.
Can every nonogram be solved with logic (no guessing)?
A properly designed nonogram has exactly one solution reachable through pure logic. If you feel forced to guess, it almost always means there's a deduction you've overlooked — recheck your largest clues and your empty marks.
Why can't I solve my nonogram?
The most common reasons are a missed empty-square deduction, forgetting the mandatory gap between separate numbers, or focusing on only rows or only columns. Switch directions and mark every square you know is empty — that usually breaks the logjam.
How long does it take to get good at nonograms?
Most people grasp the core techniques within a handful of puzzles. Solving small grids comfortably takes a day or two of practice; larger grids and faster times come naturally with consistent play over a few weeks.
Start solving
Nonograms reward you with a simple, powerful loop: read the clues, apply logic, watch a picture emerge — no guessing required. Start with small grids, lean on the overlap technique, and always mark your empty squares. Before long, you'll be reading a wall of numbers and seeing the picture hiding inside it.
tonight's picture is waiting.
One quiet color nonogram before bed. Mochi kept the lamp on.
Get Hueku on the App Store → 🌙 out now on iPhone & iPad — free to play.