What is Hexadecimal?
Hexadecimal is a base-16 number system using digits 0-9 and letters A-F to represent values ten to fifteen. Each hex digit maps to exactly four binary bits, so it is a compact, human-readable way to write binary data such as colours, memory addresses, bytes and hashes.
Because 16 is 2⁴, one hex digit equals four binary digits and one byte is exactly two hex digits. So the byte 11111111 in binary is FF in hex (255 in decimal). Hex is often prefixed with 0x.
It is used for colour codes (#FF8800), memory addresses, MAC addresses, byte dumps and hash digests — anywhere bytes need a short, readable representation.
Hexadecimal tools
String to Hex Converter
Convert text to UTF-8 hex bytes and back. Pick from five separators on encode; decode auto-strips any common separator.
Open toolNumber Base Converter
Convert numbers between decimal, binary, octal and hexadecimal in a live 4-row grid. BigInt-safe with optional signed 32 / 64-bit mode.
Open toolString to Binary Converter
Convert text to 8-bit binary and back. UTF-8 aware with optional byte and nibble spacing for readability.
Open toolColor Converter
Convert colors between HEX, RGB / RGBA, HSL, HSV, and CMYK in a live grid. Swatch preview and CSS named-color lookup.
Open toolFrequently asked questions
Why is hexadecimal used in computing?
It maps cleanly to binary — one hex digit = four bits — so bytes are short and readable (two digits) instead of eight binary digits.
What is 0x in front of a number?
The 0x prefix marks a hexadecimal (base-16) literal, e.g. 0xFF = 255.