FourByte

Fourbyte is a term used in computing to describe a data unit composed of four bytes, totaling 32 bits. This size appears in a variety of contexts, including 32-bit integers (signed or unsigned), packed color values such as RGBA, timestamps, and fields in network protocols. The interpretation of a four-byte value depends on the surrounding data type and on endianness, since little-endian systems store the least significant byte first and big-endian systems store the most significant byte first.

In file formats and multimedia, four-byte values often serve as identifiers or length fields. A common convention is the FourCC code, which encodes four ASCII characters into a 32-bit value to label a data chunk or format. FourCC codes are widely used in video, audio, and container formats to indicate the type of data that follows within a stream or file.

FourByte Directory is an online, community-maintained database that catalogs four-byte sequences found in compiled code and maps them to potential function names or libraries. Researchers and reverse engineers use the site to identify calls within obfuscated or unknown binaries by searching the 4-byte sequence. The resource relies on user contributions and cross-referencing with other signatures, though results can be uncertain without supporting context.

See also: endianness, 32-bit integer, FourCC, binary signature databases.