Toolsentropy meter

How Surprising Is Your Text?

Information is surprise. A letter you could have guessed tells you little; a surprising one tells you a lot. Entropy measures the average surprise, in bits per character. Type below and watch it move.

~/tools/entropy

1 · your text

Try:

2 · each charactersurprise = −log₂ p

charhow oftensurprise

3 · guess the next letter

Type your guess for the next letter (or space). Fewer tries = more predictable.

Tried: –

Bits per character: –
Total information (bits): –
Could shrink to: –

H = −Σ p·log₂p over single characters, compared with 8 bits per character in plain storage. Counting single characters ignores context, which makes real text far more predictable: Shannon's guessing game put English at roughly 1 bit per letter.