Gz

gz is a file extension used for gzip compressed data. It denotes files compressed with the gzip algorithm, typically produced by the gzip program as part of the GNU project.

Gzip combines the DEFLATE compression method with a simple file format. The DEFLATE algorithm is defined in RFC 1951; the gzip file format is defined in RFC 1952. A gzip file stores a header, compressed data, and a trailer containing a CRC-32 checksum and the uncompressed size. This structure enables data integrity checks after decompression.

Common usage includes compressing a single file into file.gz, or pairing tar with gzip to create tar.gz or .tgz archives that preserve multiple files and directories. The tar.gz workflow is common for distributing source code and software on Unix-like systems.

Tools and options: the gzip program supports de/compression with flags such as -d or gunzip to decompress, -c to write to stdout, -k to keep originals, and -9 to maximize compression; other options adjust timestamp, original name, and OS. gzip is widely supported across platforms, with compatible tools on Windows and macOS, and integrated into standard packaging workflows.

Related formats include zip, bzip2, and xz; tar alone is not compressed, and archive formats may use gzip as a compression layer. The .gz extension is widely recognized, and .tar.gz or .tgz extensions indicate a gzip-compressed tar archive.