In contexts where the base is not clear, hexadecimal numbers can be ambiguous and confused with numbers expressed in other bases. There is some standardization of using spaces (rather than commas or another punctuation mark) to separate hex values in a long list. Seven-segment displays use mixed-case AbCdEF to make digits that can be distinguished from each other. There is no universal convention to use lowercase or uppercase, so each is prevalent or preferred in particular environments by community standards or convention even mixed case is used.

In most current use cases, the letters A–F or a–f represent the values 10–15, while the numerals 0–9 are used to represent their decimal values. Hexadecimal is used in the transfer encoding Base16, in which each byte of the plaintext is broken into two 4-bit values and represented by two hexadecimal digits. The prefix 0x is used in C, which would denote this value as 0x8BEF. In programming, several notations denote hexadecimal numbers, usually involving a prefix. For example, the decimal value 35,823 would be expressed in hexadecimal as 8BEF 16. In mathematics, a subscript is typically used to specify the base.

For example, an 8-bit byte can have values ranging from 00000000 to 11111111 in binary form, which can be conveniently represented as 00 to FF in hexadecimal. Each hexadecimal digit represents four bits (binary digits), also known as a nibble (or nybble).

Software developers and system designers widely use hexadecimal numbers because they provide a human-friendly representation of binary-coded values. Unlike the decimal system representing numbers using ten symbols, hexadecimal uses sixteen distinct symbols, most often the symbols '0'–'9' to represent values 0 to 9, and 'A'–'F' (or alternatively 'a'–'f') to represent values from ten to fifteen. In mathematics and computing, the hexadecimal (also base-16 or simply hex) numeral system is a positional numeral system that represents numbers using a radix (base) of sixteen.

Java 7 segment display font