How to use the cryptogram solver
In a cryptogram every letter of a message has been swapped for another letter, the same swap all the way through. Type or paste the puzzle exactly as printed, with its spaces and punctuation, then press Solve cryptogram.
- The key appears under the puzzle: each cipher letter with the plain letter the solver chose. Letters that do not appear in your puzzle are dimmed.
- If you already know some letters (the puzzle often gives one as a clue), type them into the key before solving. Typed letters are locked and the solver builds the rest around them.
- If a word still looks wrong, correct one letter in the key and press Solve again.
How it solves a cryptogram
There are about 400 million million million million ways to swap 26 letters, far too many to try. The solver starts from a guess based on letter frequency (the most common cipher letter is probably E or T), then keeps swapping pairs of letters in the key whenever that makes the message read more like English. It judges this with four-letter sequence statistics built from about 5.1 million letters of public-domain books, and, because cryptograms keep their word breaks, it also rewards words that are common in English. When it gets stuck it shakes the key and climbs again from several starting points.
How accurate is it?
We tested it on passages from a novel the statistics were not built from. Messages of 100 letters or more came out fully correct. Shorter ones came out right for about 93 letters in 100 on average, which usually means a readable sentence with one or two wrong letters that you can fix in the key. Quotes with names, numbers spelled oddly or rare words are the hardest, because the solver has no way to know them.
Solving tips that work by hand too
- One-letter words are almost always A or I.
- Short words: the commonest two-letter words are OF, TO, IN, IT, IS; the commonest three-letter words are THE and AND.
- Apostrophes: a single letter after an apostrophe is usually S or T (IT'S, DON'T); two letters are often LL, RE or VE.
- Letter patterns: a word like
XYZZYhas a doubled letter in the middle; patterns such as THAT (first and last letter the same) or PEOPLE stand out. - Many puzzle books never let a letter stand for itself. If yours follows that rule, any key where a letter maps to itself is wrong.
Cryptoquotes and other names
A cryptoquote is a cryptogram whose answer is a quotation, often with the author's name encoded at the end. The same puzzle is also sold as a cryptoquip, a letter code or a substitution puzzle; they are all solved the same way. If the puzzle moves every letter by the same amount instead of swapping letters freely, it is a Caesar cipher: the Caesar cipher decoder finds the shift instantly. For Vigenère and Atbash, use the cipher solver.
This page solves what you type. It does not publish answers to any newspaper or app puzzle.
Solver tested . Found a problem? Tell us.
Questions
Can it solve a cryptogram without any clue?
Yes. Paste the puzzle and press Solve. A clue letter helps on short puzzles: type it into the key first and it stays fixed.
Why are a few letters still wrong?
Short messages give the solver little to work with, so two keys can both look like English. Fix the letter you are sure of in the key and press Solve again; your letters are kept.
Does it work on cryptoquotes and cryptoquips?
Yes. They are the same kind of puzzle: one letter always replaced by the same other letter. Include the author line if it is encoded too; more letters make the solve more reliable.
What if my puzzle uses numbers or symbols instead of letters?
This solver reads the letters A to Z. Replace each number or symbol with a different letter first (keeping the same replacement every time it appears), then solve.
Does it work in other languages?
It is tuned for English. Puzzles in other languages may come out partly wrong, because the solver scores results by English letter patterns.
Is my puzzle sent anywhere?
No. The solver runs in your browser and the puzzle is only saved in your own browser.