How to Solve Cryptograms

1. Start with the one-letter words

A word of one letter is almost always A or I. In the 155 puzzles on this site, the most common one-letter words are A, I. If the same code appears alone twice in different places, it is very likely A; if two different codes stand alone, one is A and the other I.

2. Use the apostrophes

A single letter after an apostrophe is nearly always S or T (it's, don't), and two letters are usually LL, RE or VE (we'll, they're, I've). In our puzzles the most common endings after an apostrophe are 'S, 'T, 'LL, 'VE. Watch for words like don't and can't: when the letter after the apostrophe is T, the letter just before it is usually N, so one word gives you two letters.

3. Count the letters

Some letters are far more common than others. Across all our puzzles, the twelve most frequent letters are E, T, O, A, N, I, S, H, R, L, D, U, and E alone is about 12 letters in every hundred. The rarest are Z, Q, J, X, K. The letter counts under the puzzle list each code by how often it appears: the code at the top is a good candidate for E or T, especially if it ends several words (E is common at the end of words, T at the start).

Frequency is a guide, not a rule, in a short text. Use it to choose what to try first, then confirm with the words around it.

4. Crack the short words

Once you have a letter or two, the short words fall quickly. The most common words in our puzzles are:

• Two letters: IS, OF, TO, IN, IT, AS, BE, DO.
• Three letters: THE, AND, YOU, BUT, FOR, NOT. THE appears in 50% of the puzzles; a three-letter code word that appears more than once, and whose last letter is your E, is almost certainly THE.
• Four letters: THAT, WITH, WILL, GOOD, MUST, WHAT.

With THE solved you have T, H and E everywhere in the puzzle, and the rest usually opens up.

5. Look for patterns in the longer words

Repeated letters inside a word are strong clues because the code keeps them. A word whose first and last letters are the same code, like THAT or TRUST, or one with a double letter in the middle, like LITTLE or BETTER, has only a handful of possible answers. Double letters are most often LL, EE, SS, OO and TT; a doubled vowel is almost always EE or OO.

Common beginnings and endings help as well: -ING, -ED, -LY and -TION at the end of words, TH-, WH- and ST- at the start.

6. Guess, test and undo

Cryptograms reward guessing as long as you check the guess. Put in a letter you suspect, then read the other words that contain it: if one turns into something impossible, like a word with no vowel, take it back. The puzzle above lets you change any letter at any time, Check shows which of your letters are wrong without solving anything, and a Hint fills in one code when you are stuck.

A worked example

Here is a short cryptogram: XWJ JKPMD NFPS QKXQWJZ XWJ UGPB.

1. XWJ appears twice, once at the start. The most common three-letter word is THE, so try X = T, W = H, J = E.
2. The fourth word, QKXQWJZ, now reads ? ? T ? H E ?, and its first and fourth letters are the same code. C-A-T-C-H-E-S is the word that fits, so Q = C, K = A and Z = S.
3. The second word, JKPMD, reads E A ? ? ?. EARLY is the natural word, giving P = R, M = L and D = Y.
4. Now NFPS is ? ? R ? and UGPB is ? ? R ?. "The early ? ? R ? catches the ? ? R ?": BIRD and WORM.

The answer is "The early bird catches the worm." Notice that only the first guess was a real guess; every step after it was forced by the letters already found. Real puzzles are longer, but they come apart the same way.