How the puzzles are made, checked and printed

What large print means on this site

Large print is switched on for every page. On screen it makes the cells, letters and digits bigger. On paper it widens the grid to the width of the sheet and sets the characters bold, with one puzzle to a page. The puzzle number and a short link are printed underneath and nothing else is: no advert, no logo across the grid, no second puzzle squeezed in beside it.

The size of a printed letter depends on the grid. A grid eight letters across gives bigger letters than one twelve across, because both are stretched to the same width. That is why the pages here use small grids and say how many cells across each one is. We do not quote a point size, since it changes with the grid, the paper and your printer's margins. The honest test is to print one sheet and show it to the person who will use it. The box marked Large print under each puzzle turns the larger layout off again if it is not wanted.

Puzzles are made in advance and numbered

Many puzzle sites generate a grid at the moment you open the page. We do it the other way round. All 7320 puzzles on the site, in 20 sets across 12 pages, were generated before the site was published and are stored as small data files next to each page. Your browser only draws the puzzle and keeps track of your moves.

This is what makes the number useful. Puzzle 57 of the garden word search is the same grid for everyone, today and next year. Someone who prints for a group can note the numbers they have already handed out, print the solution for the same number later, or open on a tablet the very grid that another person has on paper.

Two programs: one makes, one checks

For a word search, the generator takes one of our word lists, picks the words for that grid, places them in the allowed directions and fills the remaining cells with letters. For a sudoku it fills a legal grid at random and then removes digits one at a time, putting a digit back whenever its removal would leave more than one solution or make the puzzle need more than the simplest method.

A generator can have mistakes like any other program, so its output is not trusted. A second program, written separately, receives only what you would see on the page. For a word search it reads the finished grid from every cell in every direction and confirms that each listed word is there exactly once, so a word cannot turn up a second time by accident among the filler letters. For a sudoku it solves the puzzle from the given digits alone and keeps searching to make sure there is no second answer.

The full check runs again over every puzzle each time the site is rebuilt, and the site is not published if a single puzzle fails.

How the puzzle of the day is chosen

There is no server deciding what today's puzzle is. The page takes the date on your device, counts the days since 1 January 2026, and uses that count to pick a number from the set. A set is finite, so the sequence eventually comes round again. We state this on every page instead of pretending the supply is endless: the table at the bottom of this page lists the size of each set. Because the choice depends on your own clock, the puzzle changes at your local midnight.

What we do not claim

We do not say that puzzles improve memory, slow anything down or treat anything. We have no evidence of our own on that and it is not why the site exists. The level names describe how a puzzle was built, not how long it takes a person, and we have not timed anyone.

The nonograms are patterns and do not form pictures. The number target usually has several answers; for that puzzle we check that an answer exists and that there is no shortcut. A word scramble is checked against our own list only, so a jumble may now and then have a second answer that is a real word we did not think of. If you find a mistake of any kind, the contact page has our address, and a corrected set replaces the old one at the next rebuild.

The check for each puzzle type

Kitchen word search

A separate scan reads the finished grid from every cell in all eight directions. Every listed word must be found exactly once, at the stored position, and the grid must not spell a word from our deny list outside the listed words.

Garden word search

A separate scan reads the finished grid from every cell in all eight directions. Every listed word must be found exactly once, at the stored position, and the grid must not spell a word from our deny list outside the listed words.

Four seasons word search

A separate scan reads the finished grid from every cell in all eight directions. Every listed word must be found exactly once, at the stored position, and the grid must not spell a word from our deny list outside the listed words.

Bird word search

A separate scan reads the finished grid from every cell in all eight directions. Every listed word must be found exactly once, at the stored position, and the grid must not spell a word from our deny list outside the listed words.

Travel word search

A separate scan reads the finished grid from every cell in all eight directions. Every listed word must be found exactly once, at the stored position, and the grid must not spell a word from our deny list outside the listed words.

Easy sudoku 9x9

A second solver, written separately from the generator, starts from the given digits only. The puzzle is kept only if that solver finds exactly one solution and it is the stored one. The same checker confirms what the level promises about singles.

Sudoku 6x6

A second solver, written separately from the generator, starts from the given digits only. The puzzle is kept only if that solver finds exactly one solution and it is the stored one. The same checker confirms what the level promises about singles.

Sudoku 4x4

A second solver, written separately from the generator, starts from the given digits only. The puzzle is kept only if that solver finds exactly one solution and it is the stored one. The same checker confirms what the level promises about singles.

Word scramble

Each scrambled word is compared letter by letter with its answer, must differ from it, and the answer must be the only word in our own list that uses exactly those letters.

Number target

The stored solution is worked through again step by step with whole numbers, each number used once. A separate search confirms the target cannot be reached in fewer steps than the level promises.

Binary puzzle 6x6

A separate solver lists every legal line and searches for all grids that fit the given cells. The puzzle is kept only if exactly one grid fits and it is the stored one, and only if the three basic rules, applied again by different code, finish it without a guess.

Small nonogram

The clues are counted again from the stored picture, then a separate solver starts from the clues alone. The puzzle is kept only if it finds exactly one picture, the stored one, without ever having to guess.