dat

Dat is a widely used filename extension in computing. The term “dat” often refers to a generic data file whose contents are defined by the program that creates it rather than by the extension alone. Because .dat does not specify a data format, a single extension can hold many kinds of information, from simple text dumps to binary serialized objects.

Usage and examples include configuration data, logs, caches, and project-specific information stored by applications. Some programs export user data in a .dat file, while others store internal data in a program-specific binary format. Because there is no universal specification, the layout and interpretation of a .dat file depend on its producer.

Opening and editing a .dat file depends on its format. If the file is plain text, it can be viewed with a text editor. If it is binary, a hex viewer or a specialized loader may be required. Caution is advised: editing a .dat file can corrupt program state or data if the format or offsets are changed.

Security and risk considerations apply because .dat files can contain sensitive data or be used to store executable content in atypical circumstances. Treat unknown .dat files with care and avoid executing or altering them unless you know their source and format.

Notable uses span across systems and software, reflecting the extension’s role as a generic data container. Some well-known examples include data dumps or saved game data, and Windows’ index.dat files that store certain historical activity, though these are highly specific implementations rather than a universal standard. See also: data file, list of file extensions.