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Fill-In Crossword Generator

A fill-in — a kriss-kross, a criss-cross, a word fit, depending on which puzzle magazine you grew up with — gives you the words and an empty shape and asks where each one goes. It needs no clues at all, which makes it the puzzle to reach for when the words are this week's spellings or a set of topic terms and nobody has time to write twenty clues about them. The part that goes wrong when you draw one by hand is invisible: two words laid side by side quietly spell a third down the join, and the first person to notice is the child who finds a word in the grid that is not on the list.

What this generator does

Interlocks your words into one connected grid, prints the empty shape with the words listed underneath by length, and puts the filled grid on a second sheet.

How to use this tool

  1. Choose a word list, or type your own — one per line.
  2. Pick the paper and print size you are printing on.
  3. Make the puzzle. The grid and the word list appear together.
  4. Show the answer if you want the filled grid on a second sheet.
  5. Give a seed if you want the same puzzle again, for a second class or a resit.

Understanding the controls

Words
One of eight ready-made lists, or your own — six to sixty words of three to fifteen letters.
Paper size and print size
A4, A5, A3, US Letter or Legal, portrait or sideways, with the margin in millimetres and a compact, standard or large-print setting.
Show the answer
Adds the filled grid as a second sheet. The puzzle sheet never carries a letter.
Seed
A word gives back exactly the same puzzle, so the same one can be printed twice.

Common use cases

  • This week's spelling list as a puzzle instead of a test
  • Topic vocabulary at the start of a new unit
  • A cover lesson that needs no marking scheme
  • A puzzle page for a class newsletter
  • Something for a child who has finished early

How this generator works

The longest word goes down first, because a long word has the fewest places it can go and leaving it until the grid is full is how a list ends up with a word that will not fit anywhere. Every word after it is placed where it crosses the most words already down, and only where nothing butts up against either end and nothing runs alongside it. The finished grid is then read back and checked against the list it came from: every run of two or more letters in it, across and down, has to be one of your words, each appearing once, with nothing extra — and every square has to be reachable from every other, which is the difference between one puzzle and two printed on top of each other. A word that shares no letter with the grid anywhere it would fit is reported rather than quietly dropped.

Randomness and fairness

Where words go is decided using the browser's secure generator. A seed reproduces exactly the same grid — that path is deterministic, not cryptographic, and exists so the same puzzle can be set twice.

For how randomness is produced across the whole site, see how Generate Random works.

Limitations and good to know

  • There are no clues, and none can be added. That is the point of this puzzle rather than a shortcoming, but it is not a crossword.
  • A very short list, or one whose words share few letters, will leave some words unplaced. They are named rather than dropped silently.
  • The grid comes out whatever shape the words make. There is no way to ask for a square grid or a set size.
  • Words are stripped to their letters, so spaces, hyphens and accents do not reach the grid. The list still shows them as you typed them.
  • This page makes one puzzle at a time. For a run of them numbered straight through with a key at the back, the printable puzzle pack builds fill-in crosswords alongside sudoku, mazes, word searches, codewords and nonograms.

Privacy and your data

The puzzle is built in your browser. The words you type are never transmitted or stored.

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