Frequency Analysis — Letter & Bigram Statistics
Analyze letter and bigram frequency in any text. Bar chart visualization with English language average comparison. Useful for cryptanalysis.
English Letter Frequency Reference
E12.7%
T9.1%
A8.2%
O7.5%
I7%
N6.7%
S6.3%
H6.1%
R6%
D4.3%
L4%
C2.8%
U2.8%
M2.4%
W2.4%
F2.2%
G2%
Y2%
P1.9%
B1.5%
V1%
K0.8%
J0.2%
X0.2%
Q0.1%
Z0.1%
How to Use the Frequency Analysis — Letter & Bigram Statistics
- Enter or paste your text in the input field.
- The encoded or decoded result appears automatically.
- Copy the output using the copy button.
- Switch between encode and decode modes if available.
Référence rapide
| De | Vers |
|---|---|
| A | 65 (ASCII) |
| Z | 90 (ASCII) |
| a | 97 (ASCII) |
| 0 | 48 (ASCII) |
| Space | 32 (ASCII) |
| @ | 64 (ASCII) |
Cas d'utilisation
- •Encoding or decoding data for web development projects.
- •Learning about cryptography and different cipher techniques.
- •Preparing encoded content for APIs or data transmission.
- •Solving cipher puzzles, CTF challenges, or educational exercises.
Formule
Letter frequency = (count of letter / total letters) × 100%. In English the most frequent letters are E (12.7%), T (9.1%), A (8.2%), O (7.5%), I (7.0%). Frequency analysis is the primary technique for breaking classical ciphers.
Questions fréquemment posées
What is frequency analysis?
Frequency analysis is the study of how often each letter (or group of letters) appears in a text. Since different languages have characteristic letter frequencies, this technique is used to break classical substitution ciphers.
How is frequency analysis used to break ciphers?
In a simple substitution cipher, the most frequent ciphertext letter likely represents E in English. By mapping the ciphertext frequency distribution to the expected English distribution, you can recover the substitution key.
What are bigrams?
Bigrams (or digrams) are pairs of consecutive letters. The most common English bigrams are TH, HE, IN, ER, AN. Bigram analysis helps break more complex ciphers like Vigenère and Playfair.
What are the most frequent letters in English?
The top 10 most frequent English letters by percentage are: E (12.7%), T (9.1%), A (8.2%), O (7.5%), I (7.0%), N (6.7%), S (6.3%), H (6.1%), R (6.0%), D (4.3%).
Does this tool support Cyrillic frequency analysis?
The current tool counts Latin letters only. For Russian text, the most frequent letters are О, Е, А, И, Н, Т, С, Р — different from English.