Cryptogram Generator
Turn any phrase or quote into a crack-the-code letter-substitution puzzle, with adjustable hints and a full answer key.
About this cryptogram generator
Type any phrase, quote, joke, or fact, and this tool builds a letter-substitution cryptogram from it — every letter of the alphabet is swapped for a different one using a randomly generated cipher, and no letter is ever substituted for itself, which is the standard convention for a proper cryptogram rather than a puzzle with an accidental "giveaway" letter. Spaces and punctuation are left exactly where they are, so word boundaries stay visible and the puzzle stays solvable through pattern recognition, just like a real cryptogram.
Difficulty controls how many letters of the cipher key are revealed as hints, chosen from letters that actually appear in your puzzle (revealing a hint for a letter that isn't even used wouldn't help anyone). Easy reveals the most hints, Hard reveals none, and medium sits in between. Any revealed cipher letter is filled in everywhere it appears in the puzzle text, not just in the key legend, so a hint is immediately usable throughout the whole puzzle.
Because this works from any text you provide, it's equally suited to a famous quote, a science fact, a joke, a vocabulary word, or a message specific to your class or event — not tied to any particular subject, grade, or holiday.
Nothing you type is uploaded anywhere; the cipher, puzzle, and answer key are all generated entirely in your browser.
Every cipher is a genuine one-to-one swap of the full alphabet — each letter maps to exactly one other letter, and every letter is used as a substitute exactly once — so decoding is always a clean, unambiguous process with no letter shared between two different originals.
Frequently asked questions
Can the same letter ever decode to itself?
No. The cipher is built so that every letter is guaranteed to map to a different letter, which is the standard convention for a well-formed cryptogram.
How do the difficulty levels work?
They control how many cipher-key letters are revealed as free hints at the start. Easy reveals the most, Hard reveals none, and you solve entirely through pattern recognition and letter frequency.
Are spaces and punctuation part of the puzzle?
No, they're left exactly as typed. Only letters are substituted, so word breaks and punctuation stay visible and usable as solving clues.
Can I use my own quote or message instead of a generic one?
Yes, type anything you like — a quote, a joke, a fact, or a message specific to your class or event. There's no built-in list to choose from; it's built entirely from what you type.
Is my text saved or uploaded anywhere?
No. Everything is generated locally in your browser; nothing you type is sent anywhere.