Analyze how often each character appears in your text — sortable table, filter by type, download CSV.
Editing and transforming text manually is tedious and error-prone. Character Frequency Analyzer automates the process so you can analyze how often each character appears in your text — sortable table, filter by type, download csv in one click. It works with any length of text, from a single sentence to thousands of lines, and runs entirely in your browser for complete privacy.
Character frequency analysis counts how many times each character (letter, digit, symbol, or space) appears in a text. It's used in linguistics to study language patterns, in data science for text preprocessing, and in quality assurance to validate text encoding. It's also useful for writers who want to check for accidental character repetition, check for encoding errors, or just understand the composition of their text.
In classical cryptography, simple substitution ciphers (where each letter is replaced by another letter) can be broken using frequency analysis. Because English text follows predictable letter frequency patterns, the most common letter in a ciphertext is likely an encrypted "E," the second most common is likely "T" or "A," and so on. This technique, credited to Al-Kindi in the 9th century, was revolutionary — it meant that any sufficiently long ciphertext encrypted with a monoalphabetic cipher could be decoded without the key.
The most common letters in typical English text, in order, are: E, T, A, O, I, N, S, H, R, D, L, C, U, M, W, F, G, Y, P, B, V, K, J, X, Q, Z. The letter "E" accounts for roughly 12.7% of all letters in most English writing. This is why "E" tiles are most valuable in Scrabble and why "E" is the most useful guess in Hangman. Vowels (A, E, I, O, U) collectively make up about 38% of English text.