Nonograms vs sudoku
Two grid puzzles that reward patient reasoning. Here is what is the same, what is not, and how to pick which one to start with.
What they share
- Both are logic puzzles on a grid.
- Both are meant to be solved without guessing. A well-made puzzle always has a next step you can prove.
- Both reward the same habit: fill what is certain first, then use it to find the next certain square.
What differs
| Nonogram | Sudoku | |
|---|---|---|
| What you place | Nothing but a mark: each square is filled or empty | A digit from 1 to 9 in each square |
| The clues | Numbers beside each row and column, giving the lengths of runs of filled squares | Some digits already in the grid |
| The rule | Each line must match its numbers | No repeats in a row, column or box |
| The result | A picture | A completed number grid |
| Usual grid size | 5x5 for beginners, up to 10x10 or more (GRIDS uses 5x5, 7x7 and an optional 10x10) | 9x9 |
A nonogram row, worked out
On launch day (October 28, 2026) the GRIDS puzzle was a 7 by 7 grid, and its third row had the clue 7. Seven filled squares fit a row of seven only one way, so the whole row is filled. Its fourth row had the clue 5, so there are two squares of slack (7 minus 5). A run of five in a line of seven always covers squares 3, 4 and 5, so those three are filled before you look at a single column. That reasoning, count the slack and fill the overlap, is the nonogram equivalent of finding a sudoku square that only one digit can fill.
Which to try first
If you like checking numbers against rules, sudoku suits you. If you like pictures and counting runs, start with a 5x5 nonogram. The nonogram walkthrough solves a full 7x7 one line at a time. You can also try a nonogram right away in the 5x5 puzzles.
Background: Nonogram on Wikipedia
GRIDS: daily nonogram
GRIDS is a daily nonogram. Monday and Tuesday are the small 5x5 grids.
Play GRIDSKeep going
Questions
Is a nonogram like sudoku?
They are alike in that both are logic puzzles that can be solved without guessing. They differ in what you place: sudoku places digits 1 to 9, a nonogram marks each square filled or empty.
Is a nonogram harder than sudoku?
It depends on the puzzle and the person. A 5 by 5 nonogram is quicker to learn than most sudoku, while a large nonogram takes longer to work through. Neither needs guessing if it is well made.
Do nonograms use math?
No. The numbers only say how long each run of filled squares is. You compare lengths and count squares; you never add up to a target as in some sudoku variants.
What is a picross?
Another name for a nonogram. See the picross page for puzzles to play.