Nonogram
Deduce which cells to fill from row and column number clues, reveal the hidden picture, and watch line clues light up as you go.
FAQ
How do I read the clues?
What are cross marks for?
What does a lit clue mean?
Why does 15×15 scroll sideways?
Screenshots
How to use
- Read the clues
The numbers beside each row and above each column list the lengths of consecutive filled blocks in order. Blocks are separated by at least one empty cell, and a line without numbers is completely empty.
- Fill and mark
Start from rows and columns with big numbers and settle the cells that must be filled or must be empty. Tap once to fill, again for a cross mark, and a third time to clear.
- Use the lit clues
A clue lights up once its line matches the numbers exactly. Treat those lines as settled and push your reasoning outward from them into the unlit ones.
- Finish and track
The puzzle is solved once every filled cell matches the solution. Time and taps are recorded on the win, and the best time is kept per board size.
About this tool
Nonogram is a logic puzzle family that rebuilds a picture from numbers alone. Each row and column carries a list of block lengths. Your job is to decide cell by cell which ones are filled and which stay empty until every line matches its clue. This page offers 5×5, 10×10 and 15×15 boards generated from a seed, so the same seed always produces the same picture. Tapping a cell cycles fill, cross mark and empty, and a clue lights up as soon as its line matches.
Compared with paper versions the online board is forgiving. A wrong tap is undone with one more tap, and cross marks can be revised at any time. The timer starts on your first move, the win stores the best time for that size, and records for the three sizes never interfere. Ten by ten is the step up from casual to serious, fifteen by fifteen demands long inference chains. Clear them in order and keep every step grounded in a clue.
How it works
Nonogram clues are run length encoding. Count the consecutive filled cells on a line and remember that blocks need at least one gap between them. Those numbers are the whole specification. Because the line length is fixed and gaps are mandatory, every clue list admits only a limited set of placements. Solvers intersect those possibilities to shrink them. Boards here come from a seeded pseudo random generator with roughly fifty five percent density. An identical seed reproduces an identical picture on any device.
The workhorses of solving are complete lines, sliding window analysis near the edges, and anchoring large numbers with guaranteed gaps on both sides. Experienced players also cross check lines against columns, because a conclusion in one direction instantly constrains the clues running the other way. The win test only compares filled cells with the solution, so cross marks are free and safe. The three sizes share one rule set, and the only real difference is how long the inference chain grows.
When to use it
- Commute wind down
A ten by ten board takes roughly three to eight minutes, which fits a metro ride neatly. The rules are quiet, and a mistake costs one tap. An unfinished board can be swapped for a fresh one without any penalty before your stop.
- Family puzzle time
A five by five board takes a child a few minutes. Read the first clue together and reason out the first row as a team. Mapping numbers to blocks is gentle early math practice, and small wins keep kids asking for the next board.
- Pixel art fans
The solution of every board is a tiny pixel picture, and watching it appear on the final move is the reward. Fans can copy a finished grid onto graph paper and keep a notebook of favorite boards as a collection.
Tips & tricks
- Fill any line whose single number equals its full length, since that line is solid and settles a lot at once.
- Cross out zero clue lines first, then work outward from the settled cells.
- Stuck? Reread the lit clues and expand from the edge of the settled region.
- Never guess. If a cell is uncertain, park it and look for a line where the clue forces something.
Things to watch
- Ignoring the gaps
Seeing a three and shading any three cells breaks the rule that blocks need at least one empty cell between them. Work out where each block can sit first, since placing carefully costs less than erasing a wrong chain of fills.
- Guessing to progress
One guessed cell can poison the whole board because later clues build on it. Every puzzle here is solvable from the given clues alone. When you stall, reread all the numbers and find the conclusion you have not used yet.
- Missing the lit clues
A lit clue means the line is already fully settled, and rechecking finished lines wastes whole minutes on the big boards. Treat lit lines as locked resources and spend every remaining move on the rows and columns that are still unlit.