Convert GZ to TAR.GZ — Free Online Converter

GZ (Gzip) compresses a single file using the DEFLATE algorithm. A bare .gz file wraps exactly one compressed data stream — it does not bundle multiple files or preserve directory structure on its own. TAR.GZ (tarball) combines the TAR archiver with gzip compression, creating a single compressed archive that contains a full file tree with directory structure, permissions, and metadata.

Converting a standalone .gz file to a proper .tar.gz wraps the decompressed content in a tar archive before recompressing with gzip. This transforms a single compressed file into a standards-compliant tarball that follows the conventions expected by package managers, build systems, and source distribution platforms. If the .gz already wraps a tar archive, this conversion normalizes the output filename and structure.

Many tools and platforms distinguish between bare .gz files and proper .tar.gz tarballs. Package managers (npm, pip, gem) expect .tar.gz files with specific internal structure. Build systems look for tarballs, not standalone compressed files. GitHub release assets conventionally use .tar.gz format with a top-level project directory.

A bare .gz file also loses all metadata beyond the filename — there are no permissions, no timestamps beyond mtime, and no directory structure. Wrapping the content in TAR before gzip compression adds proper metadata preservation. This makes the output self-documenting and suitable for distribution contexts where a bare compressed file would be ambiguous or insufficient.

The gzip stream is decompressed to recover the original file data. A POSIX tar archive is created containing the decompressed file as a single entry (or multiple entries if the original .gz contained tar data). The tar stream is then compressed with gzip at the standard compression level. The output follows the conventional .tar.gz structure: tar header blocks (512 bytes each with filename, size, permissions, timestamps, checksum) followed by file data blocks, all wrapped in a gzip DEFLATE stream with CRC32 verification.