Security Analysis

String Entropy Analyzer

Entropy is a fast triage signal. Packed malware strings, stolen API keys and encrypted payloads all look random; English prose and config files do not. Paste a sample and compare.

Shannon entropy

0.00 bits/char

Length

0 chars

Unique characters

0

Total entropy

0 bits

Type or paste something to analyse.

The calculation happens in your browser with plain JavaScript. Nothing you paste is uploaded, logged or stored.

Reading entropy in practice

  • English text sits around 3.5-4.2 bits per character; Base64 of random data lands near 5.5-6.
  • A long, high-entropy string inside source code is often a leaked secret -- rotate it before anything else.
  • Packers and shellcode raise entropy sharply, which is why EDR products flag high-entropy sections.
  • Entropy alone is not proof: compressed images and legitimate tokens look identical to encrypted payloads.