Nonogram
Tap or drag to fill, toggle for marks
What is Nonogram?
A nonogram, also called picross or a griddler, is a free logic puzzle where numbers along the rows and columns tell you which squares to fill in, and the finished grid forms a picture. A clue of '4 2' means a run of four filled squares, at least one gap, then a run of two, in that order. No guessing is needed: every square can be deduced from the clues if you work in the right order.
How to play Nonogram
Controls: Tap or drag to fill, toggle for marks
- 1Read the numbers beside each row and above each column.
- 2Each number is the length of an unbroken run of filled squares, in order, with at least one gap between runs.
- 3Tap a square to fill it, or drag to fill several at once.
- 4Switch to mark mode with the button at the top left to cross out squares you have proved are empty.
- 5Fill exactly the right squares and the picture is complete.
Nonogram tips and strategy
- Start with the biggest clues. In a 10-wide row, a clue of 8 means the middle six squares must be filled no matter where the run sits - that is free information.
- Cross out what you rule out. Marking empty squares is not optional bookkeeping; it is how you find the next filled square.
- Work rows and columns alternately. Every square you resolve in a row gives new constraints to its column, and vice versa.
- A finished row or column should be marked complete. Crossing off the rest of that line stops you re-checking it and often unlocks the crossing lines.
Nonogram FAQ
How do you solve a nonogram?
Start with the largest clues, because a long run in a short line forces certain squares to be filled regardless of where the run actually sits. Mark the squares you have ruled out as empty, then alternate between rows and columns - each square you resolve constrains the line crossing it, and the puzzle unravels from there.
What does a clue like '3 1 2' mean?
Reading along that line you will find a run of three filled squares, then at least one empty square, then one filled square, then at least one empty square, then a run of two. The order is fixed and the gaps between runs are at least one square.
Is a nonogram the same as picross?
Yes. Nonogram, picross, griddler, paint by numbers and hanjie are all names for the same puzzle type.
Do you ever have to guess in a nonogram?
Not in a properly built one. Every puzzle here is generated from a fixed picture and is solvable purely by deduction, so if you are stuck the information is on the board somewhere - usually in a line you have not re-checked since resolving a crossing square.
