11111111

11111111 is a string of eight consecutive digit ones. Its meaning varies by numeral system and context, particularly in computing where it is commonly seen as a binary pattern rather than a decimal number.

In binary notation, 11111111 represents the unsigned 8-bit value 255. In hexadecimal this value is FF. In an 8-bit two's complement system, 11111111 corresponds to -1, while as an unsigned byte it is 255. As a bit pattern, 11111111 is often described as a bitmask with all bits set.

If read as a decimal number, 11111111 denotes the integer 11,111,111. This interpretation is rarely used in technical contexts where binary or hexadecimal representations are more informative, but it can occur when the sequence is treated as a decimal string.

In character encodings, the byte value 0xFF equals 255. In Unicode and Latin-1 (ISO/IEC 8859-1), the code point U+00FF corresponds to the character “ÿ.” In UTF-8, U+00FF is encoded as the two-byte sequence C3 BF. The association between 0xFF and a character is codec-dependent and may vary across systems.

Practical use of the pattern 11111111 includes forming a full bitmask in 8-bit data processing, representing maximum intensity in an 8-bit color channel, and serving as a common value in network and memory operations that require a full-byte mask. It also appears in examples and tests involving binary literals, such as 0b11111111 in languages that support binary notation.