A GZ file is a compressed archive created using the GNU Zip (GZip) compression algorithm. It compresses files to reduce their size for more efficient storage and transfer. The GZ format uses the DEFLATE compression algorithm and typically contains a header, compressed data, and footer with checksums to ensure integrity [1] [5].
GZ files are most common on Unix-based systems like Linux and macOS but can also be opened on Windows. They usually compress a single file, but a collection of files can be bundled first into a tar archive and then compressed to create a .tar.gz file.
To open or extract a .gz file on Windows, popular tools include WinRAR or 7-Zip. For example, using WinRAR, you can right-click the .gz file and choose "Extract here" to decompress it [2]. On Linux, you can use the command line tool gzip or tar, depending on whether the .gz is a single file or a tarball [4].
If you want to open .gz files online without installing software, services like Row Zero allow you to upload and unzip .gz files, particularly useful for large CSV or TXT files [6].
In summary, a .gz file in 2025 is a standard compressed file format based on gzip widely supported across operating systems and tools for compression and decompression [1] [5].