Calculate Text Entropy

Measure Shannon entropy, information density, and redundancy of your text.

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What is Text Entropy?

Shannon entropy is a concept from information theory that measures the average amount of information produced by a source of data. In the context of text, it quantifies the randomness or unpredictability of the characters in a string.

A string with high entropy is highly unpredictable (like a random password), while a string with low entropy has many repeating patterns (like "aaaaa").

The Formula

H(X) = -Σ P(xᵢ) log₂ P(xᵢ)
  • H(X): Entropy in bits per character
  • P(xᵢ): Probability of character xᵢ
  • Σ: Sum over all unique characters