Hex ↔ String / Decimal

Hexadecimal (base-16) is the standard way to represent raw bytes in a human-readable form. Each byte (8 bits) becomes exactly two hex digits (00 through FF), providing a compact and unambiguous representation of binary data. The hex-to-byte correspondence is exact — two hex characters always represent one byte — which makes hex the preferred format for displaying cryptographic hashes, memory addresses, binary protocol data, and file format magic numbers.

Hex notation appears throughout computing: CSS colors (#RRGGBB), cryptographic hash outputs (SHA-256 hashes displayed as 64 hex characters), IPv6 addresses, MAC addresses, binary file format specifications, debugger memory views, and network packet analysis tools all use hexadecimal. Understanding how to read and convert hex is a fundamental skill for low-level programming, security research, and protocol analysis.

Decimal byte representation (0–255 per byte) is used in IPv4 addresses (four decimal bytes separated by dots), pixel color values in some graphics APIs, and some configuration formats. Converting between text, hexadecimal, and decimal byte values is a common task when debugging protocol implementations, analyzing file formats, or working with hardware communication interfaces like UART and I2C.