Hex Converter

In modern computer architecture, the foundational unit of addressable memory is the 8-bit byte. One hexadecimal digit represents exactly 4 bits (a nibble), covering values from 0 (0000) to 15 (1111 or 0xF). Consequently, two hexadecimal digits represent exactly 2 × 4 = 8 bits, spanning the range 0x00 (0) through 0xFF (255). A single unpaired hex digit would represent only half a byte, so byte streams are canonically represented in even pairs.

Computers represent signed integers using two's complement binary notation rather than negative signs in memory. For instance, in an 8-bit signed integer, 0xFF represents -1, 0x80 represents -128, and 0x7F represents +127. When converting hex numbers to decimal values, you must define the target word size (such as 8, 16, 32, or 64 bits) to determine whether the most significant bit functions as a sign bit or as standard unsigned magnitude.

A raw binary byte consumes 8 bits (1 byte) in storage and memory. When converted into a printable hexadecimal string (such as "FF"), each character is stored as an ASCII character taking 1 byte each ("F" is 0x46, "F" is 0x46), resulting in 2 bytes of storage. Hex encoding provides a human-readable representation of raw bytes for debugging, serialization, and text-based network protocols at the cost of doubling storage requirements.

Standard ASCII characters (code points U+0000 to U+007F) map directly to single bytes from 0x00 to 0x7F. Unicode characters beyond ASCII require between 2 and 4 bytes in UTF-8. The first byte (lead byte) indicates the total sequence length (e.g. 0xC0–0xDF for 2 bytes, 0xE0–0xEF for 3 bytes, 0xF0–0xF7 for 4 bytes), followed by continuation bytes in the range 0x80–0xBF. For example, the character "€" (U+20AC) encodes to the three hex bytes E2 82 AC.

Big-Endian stores the most significant byte (MSB) at the lowest memory address, which matches natural left-to-right human numerical reading and standard TCP/IP network protocol headers (Network Byte Order). Little-Endian stores the least significant byte (LSB) first at the lowest address, which is the native architecture of x86, x64, and most ARM processors. When inspecting raw memory dumps or binary protocol payloads, selecting the matching endianness prevents reversed numeric calculations.

CSS hex colors map directly to color channels in the sRGB color space. A 6-digit code (#RRGGBB) allocates two hex digits (00–FF or 0–255) to Red, Green, and Blue. An 8-digit code (#RRGGBBAA) appends a two-digit Alpha channel for opacity. The 3-digit (#RGB) and 4-digit (#RGBA) shorthand forms expand each character into a duplicate pair (#F5A expands to #FF55AA), providing a concise format for uniform channel values.

Continuous hex strings concatenate byte values without spatial context. A canonical hex dump (such as the output of `hexdump -C` or `xxd`) organizes data into three distinct columns: an 8-digit byte offset address on the left, 16 hexadecimal bytes grouped into two 8-byte blocks in the center, and a 16-character ASCII preview on the right where non-printable control characters are replaced with dots (.). This allows developers to correlate byte positions with human-readable text.

In strict byte-stream parsing, an odd-length hex string cannot map cleanly to full 8-bit octets because the final nibble lacks a corresponding pair. Robust parsers handle this by either prepending a leading zero (e.g. "A" becomes "0A") or signaling a format error. Characters outside the hexadecimal alphabet [0–9a-fA-F] are filtered out or treated as delimiters (such as spaces, colons, or commas) depending on parser settings.