Cryptogram Solver
A cryptogram is a sentence where every letter has been traded for a different one, using the same swap throughout. Paste one into this free solver and it recovers the original message – or helps you crack it yourself, one letter at a time.
Opens Unscramble Words 4U, our free word-puzzle site, in a new tab. Free, with no sign-up.
What it does
Cryptograms are simple substitution ciphers: if K means E once, it means E in every word. The solver studies the shape of each coded word – its length and where letters repeat – and looks for real English words with matching shapes that also agree with each other. Then it fine-tunes the result by judging how natural the letters read. A sentence or longer is usually cracked almost instantly.
For learners, the standout feature is control. You can lock letters you’re confident about, add a clue, or uncover a single letter instead of the whole message. There’s also a button that creates a fresh practice puzzle from a familiar saying, which makes a great warm-up activity. The work happens in your browser, so nothing you paste is saved.
How to use it
- Paste or type the coded text into the main box, keeping its spaces and punctuation.
- If the puzzle comes with a clue, type it into the optional Clue field in the form G = O.
- Press Solve to see the decoded message, or Reveal one letter for a single nudge. Each additional press uncovers another letter, starting with the most frequent one in the puzzle.
- Use the key boxes below: each one represents a coded letter. Type the plain letter you think it hides, and it stays fixed the next time you solve.
- Clear the key removes your locked letters. Copy the answer puts the decoded text on your clipboard.
- Looking for practice? Press Practice puzzle to get a brand-new cryptogram.
More tips
- If a proper name or unusual word throws the result off, lock the letters you know in the key and solve again – that usually fixes it.
- Very short puzzles give you little to work with and may fit more than one sensible answer, so a clue letter helps a lot.
Ideas for the classroom and homeschool
- Grades 3–5Encode a class motto as a cryptogram and give students one clue letter. Teams use Reveal one letter only when stuck and keep a tally of how many nudges they needed.
- Grades 6–8Run a frequency investigation: students count letters in a long cryptogram, rank them, and test whether the most common symbol really stands for E before checking with the solver.
- Grades 7–10Compare a Caesar shift, which has only 25 possible keys, with a full letter swap, which has vastly more. Discuss why reasoning about word shapes beats trying every key.
- Grades 9–12Students write cryptograms for a partner, trade, solve by hand, and then use the solver to settle any disagreements – a fun way to review spelling and punctuation.
Questions
How does this compare with a Caesar shift?
A Caesar cipher slides the whole alphabet by one fixed amount, leaving just 25 shifts to try. A cryptogram can pair letters in any order, which is why the solver relies on word patterns instead.
Can a letter be left as itself?
Most published cryptograms avoid that, but the solver doesn’t depend on the rule, so it handles either case.
What if the answer is slightly off?
Lock any letters you’re sure of in the key boxes and press Solve again. Proper names and rare words are the usual cause.
Opens Unscramble Words 4U, our free word-puzzle site, in a new tab. Free, with no sign-up.
Letter-swap puzzles are great for reasoning practice but offer no real security – they shouldn’t be used to hide anything private.