Convert GZ to TAR — Free Online Converter

GZ is a single-file compression format using the DEFLATE algorithm, part of the GNU project and installed by default on every Unix-like system. TAR (Tape Archive) is the foundational Unix archival format that bundles files and directories into a single uncompressed stream, preserving file permissions, ownership, timestamps, and symbolic links.

Converting GZ to TAR decompresses the gzip layer to produce the underlying data. In most real-world scenarios, .gz files actually contain a tar archive (.tar.gz or .tgz), so this conversion effectively strips the compression to expose the raw tarball. For standalone .gz files wrapping a single file, the conversion wraps the decompressed output in a TAR container for consistent output format.

Removing gzip compression from a .tar.gz produces a plain TAR file that is useful in several scenarios. Docker's build cache works more efficiently with uncompressed tar layers since it can diff and deduplicate content. Some build systems and deployment scripts expect plain tar input that they will compress with their own preferred method (bzip2, xz, zstd). Debugging archive contents is easier with uncompressed tar since you can inspect raw file boundaries.

Plain TAR files also allow random access to individual file entries without decompressing the entire archive. While gzip requires sequential decompression from the beginning, tar's index-like central directory allows tools to seek directly to specific files — valuable when working with large archives containing many small files.

The conversion reads the gzip stream header (magic bytes 1f8b), decompresses the DEFLATE data, and verifies the CRC32 checksum and original size footer. If the decompressed content is already a valid tar archive (detected by the tar magic bytes at offset 257), it is output directly as the .tar result. If the GZ wraps a non-tar file, the decompressed content is wrapped in a new POSIX tar archive with a single entry preserving the original filename. The output is uncompressed — file sizes will increase proportional to the original compression ratio.