File entropy analyzer

Shannon entropy counts how evenly the byte values are spread, from 0 bits (one value everywhere) to 8 bits (all 256 values equally common). It cannot tell encryption from compression; both read as high entropy. That is why the report compares against a typical range per format: high entropy in an archive is normal, high entropy inside a text file points at an embedded or packed payload. A uniform block in the middle of a file is usually padding, not a secret.