Crossword maker: type your words and clues, print the puzzle and its answers

What is on a sheet

• The puzzle: an empty square for every letter, with a small number in the first square of each word. Places with no letter have no square.
• Your clues in two lists, Across and Down, each beside the number of its word. After a clue, in brackets, is how many squares the word takes.
• A line for a name and a date at the top, and a few words of your own if you type them.
• The list of words to choose from under the clues, in the order of the alphabet, if you tick that box. It is left off unless you ask for it.
• The answer sheet is the same puzzle with the letters written in, and each word written after its clue.
• The layout number in small print at the bottom, so a puzzle and its answers can be matched.

Your words and clues

• Up to 16 words, 2 to 15 letters each, and a clue of up to 70 characters for each. A line with no clue is left out, and the page says so.
• The first equals sign on a line ends the word. The clue can have more of them: FOUR = 2 + 2 = ? works.
• Only letters go in the squares. Spaces, hyphens, apostrophes and full stops are dropped: ICE CREAM takes 8 squares. A word with a digit or another sign is left out.
• Accents are taken off in the squares (Á goes in as A, Ü as U). Ñ stays Ñ. The answer sheet writes the word after its clue as you typed it, in capitals.
• The clues are yours. The page writes no clue and checks none: it cannot tell whether a clue is right, fair or kind. Read the sheet over before you hand it to someone.

How the words are crossed

• The longest word goes in first, across. Then, one at a time, the longest word that can go in is put where it crosses the most letters already there, and where the whole puzzle stays smallest.
• Two words never lie side by side. Every row of two or more squares, across or down, is one of your words and nothing else.
• The puzzle is never wider or taller than 15 squares.
• A word that shares no letter with the others, or finds no place to cross them, is left out and named above the puzzle. Another layout number, or a word that shares more letters, can make room.
• For one layout number the page tries up to 40 times, with other draws each time, and keeps the try with the most of your words in it, then the smallest one.
• It is not a newspaper crossword. There the whole square is filled and most letters belong to two words. Here most letters belong to one word, so a crossing letter helps less often.

Layout numbers, and what this page does not do

• Every layout has a number from 1 to 9999. The page picks one by chance when it opens and when you press Another layout. You can also type one.
• The same number with the same lines in the same order gives the same puzzle every time, on any device. So the answers can be printed another day.
• Many numbers give the same layout, above all with few words, because the page keeps the smallest puzzle it finds. If Another layout changes nothing, press it again.
• It does not check anyone’s work, and the puzzle cannot be filled in on the screen: it is for paper.
• It has no words or clues of its own beyond eight example lines, and it does not say which puzzle suits which age or grade. You choose.
• It keeps nothing: close the page and the words are gone.
• It has been tried in one browser’s print preview (Chromium, saved as PDF), not on paper from a real printer.

Every time the page is built, a program checks 71 examples worked by hand. Then it types 2,000 made-up lists of words and clues, some with accents, spaces, tabs and things that are not letters, and writes each puzzle and its answer sheet the way the page prints them. A second reader, written separately, takes the squares, numbers, letters and clues back off the two sheets. It checks that the puzzle sheet has no letter in it, that both sheets have the same squares and numbers, that every row of two or more squares is one typed word and every typed word is there once or is named as left out, that the numbers count up from the top left the way a crossword’s do, that each clue stands beside its own word, and that the squares all hang together in one piece no wider or taller than 15. That checks the page’s own work, not the clues and not the work done on the sheet.