Letter frequency analysis
Count the occurrences of each letter in a text and view their relative frequency, useful for cryptanalysis, linguistics or plain curiosity. 100% local processing in your browser (WebAssembly), and nothing is sent to a server.
How it works
The tool scans the text, ignores everything that isn't a letter (digits, punctuation, spaces) and counts the occurrences of each letter from A to Z, regardless of case. Results are sorted from most to least frequent, which is particularly useful for cryptanalysis of substitution ciphers (the letter "E" is the most frequent in both French and English) or for statistical linguistics exercises.
Why are some letters always more frequent?
Every language has a characteristic letter distribution: in French, the vowels "e" and "a" and the consonants "s", "n" and "t" largely dominate, while "k", "w" or "z" are rare. This regularity is precisely what makes it possible to break a simple Caesar cipher or a monoalphabetic substitution through frequency analysis.
Are accents and non-ASCII letters counted?
No, only the 26 basic letters a-z (without accents) are counted; accented letters such as "é" or "à" are not mapped to their unaccented equivalent and are therefore ignored by this counter.
100% local processing: your text is analyzed entirely in the browser via WebAssembly and is never sent to a server.