How to play Nonogram
A nonogram is a picture logic puzzle. The numbers along each row and column tell you which squares to fill; deduce them all and a small picture appears in the grid.
The rules
Each number gives the length of a run of filled squares in that row or column. The runs appear in the order the numbers are listed.
Between two runs in the same line there is at least one empty square. A zero means the line has no filled squares at all.
The puzzle is solved when every row and every column matches its numbers. The finished grid forms a picture, revealed at the end.
Controls
Tap or click a square to fill it. Tap again to mark it as empty — a note to yourself — and once more to clear the mark. Marks are only notes; the filled squares alone decide the solution. The grid warns you when a line can no longer match its numbers.
An example
Take a row of ten squares with the clue 10: every square in it is filled. A clue of 5 5 cannot fit in ten squares, because the two runs need an empty square between them — but 4 5 fits in exactly one way. Lines like these are the entry points.
Step by step
Most nonograms open the same way. The diagram follows one row of ten squares with the clue 7.
- Read the clue. A single run of seven squares must fit somewhere in a row of ten, so it can start on the first, second, third or fourth square.
- Push the run as far left as it will go, then as far right. Squares four to seven are filled in both positions, so they are filled in every position. Fill them now.
- Do the same on every row and column with a large clue. Each square you fill also sits in a crossing line, and it may be enough to fix a run there.
- When all the runs in a line are placed, mark its other squares as empty. Those marks help the crossing lines in turn, and the picture grows from both directions.
Strategy
Overlap
Compare the leftmost and rightmost place a run can take. Squares covered in both are certain. On a line of ten this works for any single run longer than five. With several runs, add them up with one gap between each: the less room is left over, the more the long runs overlap.
Edges
A filled square on the edge of the grid must belong to the first or last run of that line. If a row starts with the clue 3 and its first square is filled, the first three squares are filled and the fourth is empty.
Empty squares
Marking empty squares is as useful as filling. A square no run can reach is empty, and so is the square right after a finished run. Empty squares split a line into shorter pieces, and a piece too short for any remaining run is empty too.
Change direction
After a pass over the rows, make a pass over the columns, then back again. Few puzzles fall in one pass. The difficulty of each memraize nonogram is measured by how many of these passes a simple solver needs.
Tips
Start with the largest numbers and with full or empty lines — they fix squares no matter how the rest turns out.
Work rows and columns together. Every square you settle in a row is a fact in some column, and the two directions confirm each other.
Questions and answers
What is a nonogram?
A picture logic puzzle, also known as Picross, Griddlers, Hanjie or paint by numbers. Numbers beside each row and column describe the filled squares, and solving them all reveals a picture. The puzzle was created in Japan in the late 1980s; the name comes from Non Ishida, one of its inventors.
How do I read the clues?
Each number is one run of filled squares in a row, with no gaps inside it. The numbers are in order: left to right for a row, top to bottom for a column. The clue 3 1 means a run of three, then at least one empty square, then a single filled square.
Is there always exactly one solution?
Yes. Before a picture is published, a simple solver must finish it from the clues alone, one line at a time, without guessing. If it can, the answer is also the only one.
How big is the grid?
Every memraize nonogram is 10 × 10: large enough for a clear picture and small enough to play on a phone. On harder days a few squares may be shown at the start to give the puzzle a fair way in.
Is it free?
Yes. Every memraize puzzle is free and needs no account. Your progress is kept in your own browser, and a new puzzle appears every day.
A new puzzle every day
A new Nonogram is published every day, the same picture for every language. Past days stay in the archive.