Guide
How to Play Nonograms
A nonogram is solved by pure logic. Read the run lengths on each row and column, fill what is forced, cross out proven blanks, and cross-reference until the hidden picture appears.
Play NonogramsThe objective
Fill the squares the numbers describe
A nonogram is played on a blank square grid. Every row has a list of numbers to its left and every column has a list above it. Each number is the length of one unbroken run of filled squares in that line, and the numbers appear in the order the runs do. Your job is to work out, from the row and column clues alone, exactly which squares are filled. The finished grid shows a small picture.
You win the moment every square that should be filled is filled and no other square is. You never have to mark the blank squares to win — crossing them out is only an aid to your own reasoning. There is no penalty for a wrong fill except that the puzzle will not complete until you correct it.
The game is free, runs in the browser, and needs no account. Open the board to play; use this guide for the notation, the solving method, and the standard techniques.
Reading clues
What the numbers on a line mean
A clue of 4 2 on a row means: a run of four filled squares, then at least one blank, then a run of two filled squares, with any number of extra blanks before, between, or after. The single mandatory blank between runs is what lets you calculate how tightly a clue is packed.
Add the run lengths and the mandatory gaps to get the minimum space a clue needs. 4 2 needs 4 + 1 + 2 = 7 squares. In a 10-wide row that leaves 3 squares of slack, so any run longer than 3 has squares that are filled no matter how the clue slides — that is the overlap you fill first.
A line whose clue is a single 0 (shown here as a faint dash) has no filled squares at all; cross the whole line out immediately.
Controls
Click, drag, or use the keyboard
Every method sets the same squares. Pick whichever suits the device in your hand.
Fill
Click / tap
Click an empty square to fill it; click a filled square to clear it. Click and drag across a row or column to fill a whole run in one stroke — the drag locks to the first action so you paint or erase consistently.
Cross out
Right-click / mark mode
Right-click a square to cross it out as blank, and again to clear it. On touch, turn on the mark toggle below the board so every tap places a cross instead of a fill; drag works the same way.
Keyboard
Arrow keys / WASD
Move the highlighted cursor around the grid. Space or Enter fills the square under the cursor, X crosses it out, Backspace clears it. N starts a new puzzle, R restarts the current one, and M mutes sound.
The method
Four steps you repeat all solve
Nonograms are not searched, they are deduced. This is the whole loop.
- 1
Read the clues
Every row has numbers to its left and every column has numbers above it. Each number is the length of one unbroken run of filled squares, and the numbers are listed in the order those runs appear. "4 2" on a row means a run of four filled squares, then at least one blank, then a run of two.
- 2
Fill what is forced
Find lines where the runs can only sit one way. A clue of 8 in a 10-wide grid must cover the middle six squares no matter how it slides, so fill those. Filling one square in a row instantly narrows the column that crosses it.
- 3
Cross out the blanks
When a square cannot be filled — because no run can reach it, or its line is already complete — mark it with a cross. Crosses carry no penalty; they are how you record a deduction so a line stops fighting you.
- 4
Reveal the picture
Keep alternating between rows and columns, each fill and each cross unlocking the lines that cross it. You win the moment every filled square of the hidden picture is filled and nothing else — the crosses do not need to be complete.
Rules
Every rule that decides a square
The objective
The grid hides a picture made of filled squares. Using only the number clues, work out exactly which squares are filled. You win when the filled squares match the hidden picture; you never need to fill or cross every square, only get the filled ones right.
What the numbers mean
The numbers on a line are the lengths of the filled runs on that line, in order, each separated from the next by at least one blank square. A line with a single 0 (shown blank here) has no filled squares at all.
Rows and columns agree
Every square belongs to one row and one column, and both clues must hold. The whole puzzle is the process of making a row deduction, carrying it into the crossing columns, and carrying those back into other rows.
Crossing out
Marking a square as blank has no cost and does not need to be complete to win. It is a memory aid: it stops you re-checking a square you have already ruled out and makes the remaining possibilities in a line easier to see.
One logical solution
Every puzzle here is generated and then verified to be solvable by line-by-line logic with no guessing, so it has exactly one reachable solution. If a move seems to require a coin flip, a safe deduction exists elsewhere.
The timer
The clock starts when the puzzle is dealt and stops when you solve it. Your fastest solve for each grid size is saved on your device. Restarting the same picture or dealing a new one resets the clock.
Techniques
The standard deductions
Learn these five and most puzzles unravel without ever needing a guess.
- 01
Simple overlap
For one run of length L in a line of length N, wherever it slides it always covers the centre 2L − N squares. Fill those. In a 15-line, a clue of 10 forces 5 centre squares before you look at anything else.
- 02
Edge anchoring
If the first clue on a line is a run and the first square is filled, that run starts at the edge — fill its whole length and cross the square after it. The same works mirrored from the far end.
- 03
Clue splitting
A filled square that already sits inside a solved run lets you place a gap after it, which pushes the next clue further along and often anchors it against a wall or another filled square.
- 04
Full-line completion
When the filled squares on a line add up to the sum of its clues, every remaining square is blank. When the blanks make the runs unable to fit any other way, the rest is filled.
- 05
Forcing from gaps
Count the minimum length a clue needs (runs plus one blank between each). Subtract from the line length to get the slack. Any run longer than the slack has forced centre squares.
Common mistakes
Why a solve goes wrong
Filling on a hunch
A nonogram punishes guesses more than most puzzles: one wrong filled square corrupts both its row and its column, and the contradiction can surface far away, long after you can remember which move caused it.
Ignoring the crossing line
Players often solve a row, then move straight to the next row. The value was in the columns that row just changed. After any fill, look up and down before you look sideways.
Not crossing out blanks
Leaving proven-blank squares empty makes a line look like it still has options it does not. Crossing them is what makes the next deduction visible.
Forgetting the gaps count
A clue of "3 3" in a line needs 3 + 1 + 3 = 7 squares minimum. Counting the mandatory single-square gaps between runs is what tells you whether a clue is tight enough to force squares.
Chasing the picture
Trying to guess what the image is and filling squares to match it is a fast way to lose. Solve the logic; the picture appears on its own.
Grid sizes
Three sizes, one ruleset
Pick the size from the control above the board. The deduction rules never change; the grid just gets deeper.
Mini · 5 × 5
A 25-square grid that fits any phone with room to spare. Clues rarely exceed two numbers, so it is the place to learn the notation and the overlap rule. A confident solver finishes one in well under a minute.
Classic · 10 × 10
The standard nonogram. Big enough for a recognisable picture and for column-and-row cross-referencing to matter, small enough to solve in a single sitting. This is the default grid.
Grand · 15 × 15
A 225-square grid with longer clue strings and deeper chains of deduction. It pans within its frame on a phone so the squares stay tappable, and rewards disciplined crossing-out.
Where you can play
Same puzzle on phone and desktop
playnonogram.app runs in any modern browser with no app to install. Progress stays on the device you played on.
Desktop browsers
Chrome, Edge, Firefox, and Safari all run the game with no plugin. Click fills, right-click crosses out, and click-drag paints a run. Keyboard control with a moving cursor is available for hands-free solving.
Phones and tablets
Tap to fill and use the mark toggle to cross out, or drag to fill a run. Mini and Classic fit a phone screen without scrolling; Grand pans inside its frame so cells stay large enough to tap accurately.
Saved on this device
Your fastest solve for each grid size, puzzles started and solved, and your current and best solve streaks are stored in your browser. They stay until you reset them or clear site data, and they do not sync between devices.
A quick recap of the tips
- Start with the biggest numbers. A clue close to the length of its line has the least room to move, so it forces the most squares before you have done any cross-referencing.
- Use the overlap rule: for a run of length L in a line of length N, the middle (2L − N) squares are always filled, whichever way the run slides. It works on any single clue and is the fastest way to open a fresh grid.
- After every fill, look at the crossing line. One new filled square often turns a loose column clue into a forced one.
- Cross out aggressively. A line whose filled total already equals the sum of its clues has every other square blank — mark them and move on.
- Work edges and corners first. A run touching the end of a line is pinned there, so its position is known immediately.
- When a clue is satisfied, its label dims here — treat that as a signal to stop reading that line and spend your attention elsewhere.
- Never guess. Every fair nonogram is solvable by logic alone; if you are stuck, there is a deduction you have not spotted, usually one line over from where you are looking.
Still stuck on a rule? Read the nonogram FAQ or jump in and play.
Play nonograms free