What's a cipher crossword?
Take a finished crossword. Rub out every letter. Now stamp a little number in the corner of each cell — the same number wherever the same letter used to be — and hand it over. That's a cipher crossword: the grid is really a message written in a substitution code, and your job is to break it. There are no clues to know or not know; every scrap of evidence is already on the page, waiting to be noticed.
The puzzle goes by a small crowd of names — codeword is the usual one in British magazines, with codebreaker and code cracker close behind — and it has been a back-page staple for decades, usually sitting right beside the regular crossword and quietly outlasting it in the affections of anyone who tries both. Whatever you call it, the deal never changes: one number per letter, one letter per number, no exceptions.
How to crack the code
- Squeeze the starter letters first. Every blue letter we give you is already sitting in several cells. Look at the words those cells belong to — a word showing _ E E or T _ E has far fewer possibilities than an empty one.
- Hunt for repeated numbers inside one word. A word whose first and last cells carry the same code, or one with a doubled number in the middle (13 13), narrows things dramatically — think OO, EE, LL, SS.
- Count the crowd. The code you see most often across the grid is very likely a common letter — E, A, S, T and friends. The one that appears exactly once is probably something exotic. Frequency is the codebreaker's oldest trick, and it works just as well here as it did on actual ciphers.
- Use the letter list. Under the code key we show every letter this puzzle uses, and they cross themselves off as you place them. When you're down to the last three or four, the endgame becomes a tidy process of elimination.
- Guess like a scientist. Stuck? Pencil in a hypothesis — "suppose code 7 is R" — and follow it into the crossings. A wrong guess collapses quickly in a codeword, because one bad letter pollutes every cell that shares the code. That's not a flaw; that's the fun.
One letter cracked everywhere at once
The special pleasure of a codeword is the chain reaction. In a normal crossword, solving 4 Across gives you 4 Across. Here, deducing that code 9 is H fills in an H in every cell marked 9 — sometimes five or six cells lighting up across the grid at once, each one turning some other half-word into a three-quarters-word. Our player leans into this: type a letter in any cell and it lands in all of that number's cells automatically, and the code key on the right fills in as your crack sheet.
Why our codes go from 1 to N (not always 26)
A full-size newspaper codeword uses a 13×13 or 15×15 grid, big enough to smuggle in every letter from A to Z — which is why its key always runs 1 to 26. Our puzzles are deliberately small and friendly (5×5 to 9×9), and a grid that size simply can't contain the whole alphabet; there's no room for a Q, a J and a Z in twenty cells. So we do the honest thing instead: the codes run from 1 up to however many different letters the grid actually uses — usually somewhere between 9 and 22 — and we show you exactly which letters are in play. You get the same one-number-one-letter logic, minus the dispiriting hunt for letters that were never there.
Why are some letters given?
Tradition and mercy, in equal parts. Printed codewords always reveal two or three letters, because a substitution cipher with no foothold at all is a long stare followed by a guess. We always give you the grid's most common letter — the strongest possible anchor — plus a couple of others chosen at random, between two and five depending on the size. They're shown in blue, they fill their cells from the start, and they won't budge if you type over them. Everything after that is yours to earn.
Cipher crossword, cryptogram, codeword — who's who
The family resemblance causes confusion, so here's the lineup. A cryptogram is a sentence or quotation written in a substitution cipher — same codebreaking idea, but the text is a single line of prose and you lean on grammar ("a one-letter word is A or I"). A cipher crossword (this page) applies the cipher to a crossword grid instead, so your leverage comes from crossings: every cell belongs to two words, and each word polices the other. And a plain codeword? That's the magazine name for exactly this puzzle — we tell that side of the story on our codeword puzzles page. If you'd rather scramble than decrypt, our anagram crosswords and scrambled crosswords are cousins from the other side of the family.
For parents and teachers
Codewords are a gentle introduction to real cryptography — this is genuinely how substitution ciphers get broken, frequency counts and pattern-spotting and all, just with a friendlier grid. They're also sneaky spelling practice: you can't confirm that code 12 is K without mentally testing whole words, letter by letter. For a classroom set, open Download a puzzle pack under the puzzle — pick a size, add a name & date line, and keep the answer key page for yourself. The printed version includes the code key boxes and the letter list, ready for pencils. It's all free, and we're happy to hear what would make it more useful.
Common questions
Do I need to guess, or can it be solved by pure logic?
Mostly logic, occasionally a small educated leap. The starter letters plus letter frequencies carry you a long way, and because ours are small grids with everyday words, the leaps are short — "is this THE or SHE?" rather than anything heroic. If a hypothesis is wrong, the crossings expose it within a move or two, and the Check button will referee any dispute.
Where did the clue numbers go?
A codeword doesn't have clue numbers — the number in each cell is a code, not a reference to a clue list. Every cell gets one, and identical numbers mean identical letters. If you're missing proper clues, the mini crossword is the classic experience.
Why does typing one letter fill in several cells?
Because that's the codeword contract: same number, same letter, everywhere. The player just saves you the pencilwork — deduce it once and it lands in every matching cell. Deleting works the same way, so a retracted theory cleans up after itself.
Can I print these?
Yes — Download a puzzle pack just under the puzzle builds a PDF with the coded grid, the key boxes (starter letters filled in), the letter list to cross off, and an optional answer key as a separate final page. Choose 1–10 puzzles, large print if you like, and puzzles you print won't reappear online on this device.
Will I see the same puzzle twice?
No — your device remembers every cipher crossword you've played here and the engine refuses to deal a repeat. Each grid also gets its own fresh code (the same word would wear different numbers in different puzzles), so nothing carries over except your growing knack for it. Curious about the machinery? See how we make our puzzles.