AZ Tools

Letter Frequency Analyzer

Text

Paste any text and see a per-character histogram: count, percentage, and a bar per row. Toggle which character classes to include (letters / digits / whitespace / punctuation / other Unicode). Case-folding optional. When letters are enabled, a side-by-side comparison against the standard English letter distribution (E 12.7%, T 9.1%, A 8.2%…) is shown — handy for classical cryptanalysis, language identification, font coverage planning, or just nerd curiosity.

Total chars: 0Unique chars: 0

Paste text above to see the character histogram.

How to use

  1. Paste your text in the top panel.
  2. Toggle which character classes you want to count (letters / digits / whitespace / punctuation / other).
  3. Read the histogram and the English-frequency comparison. Copy CSV for further analysis.

Frequently asked questions

What does the English comparison reveal?
Plaintext English follows a very stable letter distribution (E dominates, then T, A, O, I, N, S, H, R). If your text matches, it's likely English plaintext. If a substitution cipher is applied, the bars get scrambled but the SHAPE survives — that's the whole basis of classical cryptanalysis.
Does it handle Unicode?
Yes. Characters are split as code points (so emoji and CJK count as one each), and the 'other' bucket captures anything outside letters/digits/whitespace/punctuation. The English comparison only reads ASCII a-z though.
How are whitespace and control chars shown?
Space appears as ␠, tab as ⇥, newline as ↵, carriage return as ⏎. Other non-printable code points show as U+XXXX.
Why is my distribution flat?
Random text, encrypted ciphertext, base64, and hex all flatten the curve compared to natural language. A flat letter distribution is itself a strong signal that the text isn't English prose.

Related tools