.taZ File Extension

What kind of file is a .taZ?

A .taZ file is normally a TAR archive compressed with the historical Unix Compress utility. It is a short spelling of .tar.Z: TAR supplies the member directory, filenames, and metadata, while Compress wraps that complete TAR stream using adaptive Lempel-Ziv-Welch coding.¹

The conventional media type is application/x-compress, although it is not registered by IANA.² A Compress stream begins with hexadecimal bytes 1F 9D. Check those bytes and validate the stream because a suffix alone cannot establish the actual format.

How do I open a .taZ on my computer?

• On Windows, 7-Zip can unpack both TAR and Unix Compress (Z) data.⁴
• On macOS and Linux, GNU tar can recognize the compression signature and invoke a compatible decompressor. GNU gzip can decode traditional Compress streams, while ncompress provides the original-style uncompress utility.¹³

List archive members before extracting an unfamiliar file:

tar -tf backup.taZ

Then extract into a new, empty directory. Review the listing for absolute paths, .. parent-directory references, symbolic links, and unexpected executables. A small compressed file can also expand into a much larger archive, so apply sensible storage and resource limits.

Poly support for .taZ

Poly stores, syncs, shares, versions, downloads, and finds .taZ files by name. Poly does not currently infer Unix Compress from this shorthand, decompress its payload, index its TAR members, generate a thumbnail, or provide an in-app archive preview. The Poly agent cannot read the compressed contents.

If you need content search, previews, or agent access, extract the archive with a trusted local tool and add the resulting supported files to Poly separately.

History of .taZ

The .taZ spelling combines the TAR name with the uppercase .Z convention used by Unix Compress. Spencer W. Thomas released the first compress implementation in July 1984, and a portable version entered the BSD lineage in 1985.⁵ The utility became common for Unix software distributions and backups.

Patent concerns surrounding LZW later helped motivate GNU Gzip as a free replacement. Modern GNU tar retains .taZ and Compress support mainly for compatibility with older collections.¹³

Working with .taZ and alternatives

Unix Compress has no checksum over the original uncompressed bytes. A successful decode therefore does not prove that an archive is intact or authentic. Verify an external digest when one is available, then inspect the TAR member list before extraction.³

For a modern replacement, decompress the outer stream to recover the TAR archive, then recompress that stream:

Renaming backup.taZ to one of these suffixes does not convert it. Preserve the TAR payload, choose the new compressor explicitly, and keep a verified original when handling archival material.