| Extension | .gz |
| Category | archives |
| Description | The GZ file format, also known as GZIP, is a common format for compressing files, improving storage efficiency and data transfer speed. This format uses the DEFLATE algorithm, combining LZ77 and Huffman encoding, to achieve these benefits. Consequently, it saves disk space and accelerates network downloads. Most operating systems and software applications support the GZ format for compression and decompression, making it a vital tool for data compression and archiving, especially where file size and processing speed are critical. |
| Technical details | Developed as a free software standard to replace the UNIX compress format, the GZ format adheres to RFC 1952. Various programs, including GNU gunzip, 7-Zip, and WinRAR, can extract compressed GZ files. Each file starts with a 10-byte header containing a unique identifier (magic number), the compression method, timestamps, flags, and potentially comments, the original file name, and a checksum. CRC-32 ensures data integrity. The GZ format supports concatenating multiple GZ archives into a single file. Theoretically, it can compress files of any size. However, due to limitations of the 32-bit CRC, it's not recommended for files larger than 4 GB. GZ is frequently used to compress TAR files, creating TAR.GZ archives, often called "tarballs." This format is primarily used for software packaging in Linux and Unix-like operating systems. |
