Last updated 28 August 2026
Why letter frequency is worth looking at
Ordinary English prose has a strikingly stable letter distribution: E leads at around twelve per cent, followed by T, A, O, I and N, and the pattern holds across almost any large sample of natural text. That stability is what makes frequency analysis the first step in breaking simple substitution ciphers, and it is also a quick sanity check on whether a text is what it claims to be — a passage with a flat distribution or a wildly over-represented letter is usually generated, encoded, or written under a constraint. Word mode answers a different question, closer to what a keyword-density check does: which terms actually dominate a piece of writing, as opposed to which ones you intended to emphasise.
Common questions
What is the difference between the three counting modes?
Letters-only counts A to Z and ignores everything else, which is the mode used for cipher and language analysis. Every character counts spaces, digits and punctuation too. Word mode splits on whitespace and punctuation and counts whole words instead.
What is the usual English letter order?
Roughly E, T, A, O, I, N, S, H, R — with E at about twelve per cent of all letters. Comparing a text against that order is the classic first move when analysing a substitution cipher.
Can I get the results out as a file?
The copy button puts the full ranked table on your clipboard as comma-separated values, which pastes straight into a spreadsheet as two columns.
Is my text uploaded anywhere?
No. The whole analysis runs in your browser and nothing is transmitted.