How to solve cryptograms: letter frequency, short words and patterns

Here's how to solve cryptograms: start with what English gives away. E and T are the most common letters, a one letter word is almost always A or I, and an apostrophe is usually followed by S, T, D, M, LL, RE or VE. Pencil in those guesses, find a repeated THE, then let pattern words fill the rest.

That's the whole method. The rest of this page is the detail, plus a puzzle I made up and solve in front of you.

Key points

• A cryptogram here means a letter substitution puzzle: every letter in a quote is swapped for another letter, the same way throughout.
• Count the letters first. E, T, A, O, I and N are the most common in English.
• Short words and apostrophes crack open most puzzles faster than frequency does.
• Pattern words, where letters repeat, like THERE or LOOKED, confirm or kill a guess quickly.
• Write in pencil. Every solver guesses wrong, so the skill is spotting it early.

What kind of cryptogram is this?

In English, a cryptogram is a quote or sentence written in a simple substitution cipher: each letter stands for one other letter, and the key stays the same for the whole puzzle. Word breaks and punctuation are kept, and in most puzzles no letter stands for itself. That's the kind this guide solves.

Wiktionary lists both meanings, and the word trips people up. In the Netherlands and Belgium, a cryptogram is a cryptic crossword, with clues built on wordplay. If you came here for those, this is the wrong page, sorry.

The American Cryptogram Association calls the English kind an Aristocrat when the word divisions are kept, and a Patristocrat when the text is run together in groups of five letters. Newspaper and app cryptograms are nearly always Aristocrats, which is good news, because word lengths are your strongest clue.

Which letters should I guess first?

Guess E and T first. In a sample of 40,000 English words analysed by Cornell University's mathematics department, E made up 12.02% of letters and T made up 9.10%, followed by A, O, I and N. So the most common letter in your puzzle is a decent bet for E, and the second for T.

Here's the top of that Cornell table:

Letter	Share of English text
E	12.02%
T	9.10%
A	8.12%
O	7.68%
I	7.31%
N	6.95%
S	6.28%
R	6.02%
H	5.92%

The old shorthand ETAOIN comes from this order. The American Cryptogram Association's beginner guide gives ETAONIRSH as the high frequency letters, which is the same idea with a slightly different order.

A warning, though. A cryptogram is usually one sentence, maybe 60 to 120 letters, and short texts wobble. I treat frequency as a hint for the top two or three letters, never as proof.

What do short words and apostrophes give away?

Short words are the quickest way in. There are only two one letter words in English, A and I, as Cornell's hints page points out. Two letter words are limited too, and every word needs a vowel. After an apostrophe you'll nearly always see S, T, D, M, LL, RE or VE.

A few tells I check on every puzzle:

• One letter word: A or I. If the sentence starts with it, I lean towards I.
• 'T at the end: the letter before it is almost always N, as in DON'T, CAN'T, WASN'T.
• 'S at the end: a possessive or IS, and it hands you S for free.
• Repeated three letter word: THE, then AND. If it appears twice, it's very likely THE.
• Q: in English it is followed by U.

How do double letters and pattern words help?

A double letter narrows a word fast. Cornell lists SS, LL, OO, EE, NN and PP as frequent doubles, while AA and YY are rare. Pattern words go further: write the word as numbers, one per new letter, and match the shape. THERE is 12343, THAT is 1231, and only a few words fit.

The American Cryptogram Association's guide suggests memorising a handful: 1231 is THAT, 12343 is THERE or THESE, 122 is ALL, OFF, SEE or TOO. Once you have two or three letters in a pattern word, the rest of the word usually falls out, and those letters spread across the puzzle.

Can you show a worked example?

Yes. I made this one myself with a random key, so it isn't from any book or app, and no letter stands for itself. I solve it below in seven steps, using frequency, a repeated THE, an apostrophe, a pattern word and a double letter, in roughly the order I'd spot them. Here's the ciphertext:

Z XAANHI JR RTH AXI PJG, FCR RTH ZDXJQI UJDQ'R RTHLH.

Plain letters in my notes are lowercase, cipher letters are capitals.

1. Count. R appears 6 times and H appears 5 times. I pencil in R = t and H = e.
2. Repeated three letter word. RTH appears twice and reads t?e. That's THE, so T = h.
3. Apostrophe. UJDQ'R ends in 't, so Q = n.
4. Pattern word. RTHLH reads the?e with the 12343 shape. THERE fits, so L = r.
5. Short words. Z stands alone, so it's A or I. JR is a two letter word ending in t: AT or IT. One of them must be the other vowel, so I try Z = i and J = a, and keep the swap in mind.
6. Double letter. XAANHI has a double in the middle and H = e near the end. If I = d, it's a six letter word with a double letter, ending in ed. LOOKED fits, so X = l, A = o, N = k, I = d.
7. Check. AXI is now old. PJG is ma? next to old, so MAP. FCR is ?ut: BUT. ZDXJQI is i?land: ISLAND. UJDQ'R is ?asn't: WASN'T.

The answer: I LOOKED AT THE OLD MAP, BUT THE ISLAND WASN'T THERE.

Notice that frequency only gave me two letters, and T edged out E here because a short sentence is a small sample. The apostrophe, THE and the pattern word did most of the work. That's typical.

What are the tells to look for, all in one place?

The tells worth memorising are the common letters E and T, the one letter words A and I, N before 'T, a repeated THE, the frequent doubles, and a few pattern shapes like 12343 for THERE. This is the table I'd stick next to a puzzle book, with where each tell comes from.

Tell	What it usually means	Why
Most common cipher letter	E, then T	Cornell frequency table
One letter word	A or I	Only two in English
Letter before 'T	N	DON'T, CAN'T, WASN'T
Repeated three letter word	THE, then AND	Most common short words
Double letter	SS, LL, OO, EE, NN, PP	Cornell list of frequent doubles
Shape 12343	THERE, THESE	ACA pattern list
Shape 1231	THAT	ACA pattern list
Shape 122	ALL, OFF, SEE, TOO	ACA pattern list
Letter always before one other	Q then U	Q is followed by U in English
Rare letters	Z, J, Q, X	Each under 0.2% in Cornell's sample

If you get stuck, rub out your weakest guess rather than your newest one. The mistake is often the confident early one, not the last.

A game built on the same decoding instinct

I built Cipher Isles around the same instinct: one solved piece makes the next one easier. It's a word puzzle game where you swipe words on a hex grid, and each filled tablet decodes a glyph of Vael, an invented language. It isn't a substitution cipher, but it scratches a similar itch.

You play as Mara, a cartographer shipwrecked on a chain of islands, and you repair your ship as you go. It plays offline with no account. It's on Google Play for Android. There's more on the Cipher Isles page, and I explain how it plays in what is Cipher Isles. If you'd rather train numbers than letters, I also wrote about CalcFit, my mental math app.

Frequently asked questions

What is the first step to solving a cryptogram?

Count how often each cipher letter appears and mark the top two. Then look at one letter words, words with an apostrophe and any repeated three letter word. Those clues usually give you E, T, A or I, N and H before you've written anything else.

Can a letter stand for itself in a cryptogram?

In most published cryptograms, no. The American Cryptogram Association's rules for the Aristocrat say no letter may stand for itself, and many puzzle books follow that. If a puzzle allows it, it will usually say so in the instructions.

Is a Dutch cryptogram the same thing?

No. In Dutch, a cryptogram is a cryptic crossword, where each clue is a piece of wordplay. The English cryptogram is a substitution cipher you decode letter by letter. The skills overlap a little, but the puzzles are different.

How long should a cryptogram take?

My own rough estimate: a newspaper length cryptogram takes a beginner 15 to 30 minutes, and a practised solver about 5 to 10. It varies with length and how well you know the common patterns. Once you spot THE, apostrophes and pattern words on sight, most of the solving happens in the first few guesses.

What if my letter frequency guesses are wrong?

They often are, because a single sentence is a small sample. Use frequency only for your first one or two guesses, then trust short words and pattern words more. If a guess makes a word with no vowel, rub it out.

How I wrote this

On 4 November 2026 I read Cornell University's letter frequency table and solving hints, the American Cryptogram Association's beginner guide and the Wiktionary entry for cryptogram, and checked search volumes in Google Keyword Planner for the United States. I made the worked example myself with a random key. The Cipher Isles details come from its Google Play listing and the game I built.

By John Osakwe, founder of Etest Tech Hub. I have built apps and websites since 2015, including Etest CBT, FizzFree and Pawlarm.