Character Frequency Analyzer

Count character, letter and word frequencies for text analysis

Text

Summary

123
Characters
100
No spaces
24
Words
3
Lines
96
Letters
0
Digits
23
Whitespace
34
Unique

Top characters

  • space
    21 (17.1%)
  • "o"
    9 (7.3%)
  • "e"
    6 (4.9%)
  • "u"
    6 (4.9%)
  • "i"
    5 (4.1%)
  • "a"
    4 (3.3%)
  • "h"
    4 (3.3%)
  • "r"
    4 (3.3%)
  • "b"
    3 (2.4%)
  • "c"
    3 (2.4%)
  • "d"
    3 (2.4%)
  • "f"
    3 (2.4%)
  • "g"
    3 (2.4%)
  • "j"
    3 (2.4%)
  • "k"
    3 (2.4%)
  • "l"
    3 (2.4%)
  • "m"
    3 (2.4%)
  • "n"
    3 (2.4%)
  • "q"
    3 (2.4%)
  • "t"
    3 (2.4%)
  • "v"
    3 (2.4%)
  • "w"
    3 (2.4%)
  • "x"
    3 (2.4%)
  • "y"
    3 (2.4%)

Letter frequency (a–z)

a4.2
b3.1
c3.1
d3.1
e6.3
f3.1
g3.1
h4.2
i5.2
j3.1
k3.1
l3.1
m3.1
n3.1
o9.4
p3.1
q3.1
r4.2
s3.1
t4.2
u6.3
v3.1
w3.1
x3.1
y3.1
z3.1

About

Analyze the character, letter, and word composition of a text. Shows summary counts (characters, words, lines, letters, digits, whitespace), the most frequent characters, and an a–z letter frequency breakdown useful for cryptography and linguistics. Everything runs in your browser; nothing is uploaded.

Examples

Count characters in a paragraph

Input
The quick brown fox jumps over the lazy dog.
Output
Total: 45 chars | Letters: 35 | Words: 9 | Lines: 1
Top chars: ' ' (8), 'e' (4), 'o' (4), 't' (4)
Letter frequency (a-z): [a:1 b:1 c:1 d:1 e:4 f:2 g:1 ...]

Whitespace is the most frequent character (8 spaces), followed by 'e', 'o', and 't' — matching the pangram's well-known letter distribution.

Frequency analysis on a cipher text

Input
 ciphertext:
PHHW PH DMH SHDFKWH — a Caesar-cipher ciphertext
Output
Top chars: 'H' (5), 'D' (3), 'P' (2), 'S' (2)
Expected English top: E, T, A, O, N
H appears most — likely E in plaintext → shift 3

The bar chart suggests H maps to E (shift 3), a strong clue for breaking the cipher.

About this tool

Character Frequency Analysis counts every character in a text — letters, digits, whitespace, punctuation, and special characters — and reports the total, plus the top N most frequent characters and an a–z letter-frequency bar chart. It is useful for developers inspecting text quality, linguists doing corpus analysis, and cryptographers performing frequency-analysis attacks on classical ciphers.

The chart is case-insensitive (A and a are merged), which is the standard approach in cryptanalysis: English 'E' is the most frequent letter regardless of case. The chart renders as a CSS bar chart directly in the browser, with no server calls.

How to use

  1. Paste your text

    Drop any text — a paragraph, a source file, a log, or a cipher text — into the input area.

  2. Read the statistics

    The tool shows counts for total characters, words, lines, letters, digits, whitespace, and unique characters. The top-10 characters and the a–z frequency bar chart appear below.

  3. Use the chart for cryptanalysis

    If the text is a monoalphabetic substitution cipher, compare the frequency bars against the known English letter distribution to guess which letters map to which.

Use cases

Cryptanalysis of classical ciphers

Run frequency analysis on a monoalphabetic substitution cipher to guess the most likely plaintext letter for each cipher character.

Checking text quality in a data pipeline

Confirm that an extracted text contains expected letters and digits, or spot unexpected characters like control codes or zero-width spaces.

Language detection from character distribution

German, French, Spanish and English each have distinct letter frequencies. A quick frequency chart helps guess the language of an unknown text.

Common mistakes

Mistake:Using case-sensitive mode for cryptanalysis.

Fix:Frequency analysis for classical ciphers must be case-insensitive. In English, 'E' and 'e' are the same character for frequency purposes. The tool defaults to case-insensitive.

Mistake:Treating whitespace as ignorable.

Fix:Whitespace is a character. In many ciphers and encoded messages, spaces are preserved and their frequency (roughly one per word) is a useful signal.

Mistake:Expecting frequency analysis to solve polyalphabetic ciphers.

Fix:Frequency analysis breaks monoalphabetic substitution (Caesar, simple substitution) but not Vigenère or modern ciphers, which use multiple alphabets. For Vigenère, determine the key length first.

Frequently asked questions

Related guides

Caesar Ciphers, ROT13, and Why Neither Is Encryption

What a shift cipher is, why ROT13 is self-inverse and useful for light obfuscation, and how frequency analysis breaks even large keys efficiently.

Letter Frequency Analysis: How Frequency Stats Crack Substitution Ciphers

What the letter distribution in English looks like, how to use it to break a Caesar cipher, and what word and line stats reveal that individual letters miss.

References & standards

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