What is the TXZ file format?
A .txz file is a TAR archive compressed with the XZ algorithm - functionally identical to .tar.xz and simply a shortened alias for that double extension. The format bundles multiple files and directories into a single TAR container, then applies XZ/LZMA2 compression to the entire stream, yielding significantly better compression ratios than the older .tgz (gzip) and .tar.bz2 (bzip2) formats.
XZ compression uses the LZMA2 algorithm, optionally preceded by pre-filters (BCJ for executable code, delta for binary data) to improve ratios on specific content types. The resulting file carries the standard XZ stream header (` \xFD7zXZ\x00 `) regardless of inner TAR content, and integrity is protected by per-block CRC-64 checksums.
Slackware Linux adopted .txz as its native package format starting with Slackware 13.1 (2010), making it the first major distribution to use XZ-compressed packages. The pkgtool/installpkg suite handles .txz packages natively on Slackware. Elsewhere, .txz and .tar.xz are fully interchangeable - tar -xJf archive.txz extracts either form on any modern system.
The format has no built-in encryption. XZ decompression is reasonably fast; compression is slower than gzip but the ratio advantage makes .txz dominant for Linux kernel source releases and many open-source project tarballs. .tar.zst (Zstandard) is gaining traction as a faster alternative.
Security & safety
RISK: LOWThe XZ/TAR format combination carries no executable logic itself. Risk is identical to any archive: contents may include executables or scripts that should not be run from untrusted sources. Beware path-traversal in malformed TAR members (tar slip); use modern extractors that strip leading slashes. The 2024 CVE-2024-3094 xz backdoor affected the xz/liblzma build tool binaries (versions 5.6.0/5.6.1), not .txz files or the XZ file format itself.
Format details
in a nutshellPrograms that open TXZ files
Windows2 apps
7-Zip
Open-source Right-click the .txz → 7-Zip → Extract Here (extracts xz layer to .tar, then extract the .tar again). Or use 'Extract to folder' to do it in one UI step. 
macOS3 apps
The Unarchiver
Free Double-click the .txz; The Unarchiver decompresses and extracts the tar in one step. 
Terminal (tar)
Built-in tar -xf file.txz - macOS bsdtar transparently handles the xz compression layer. 
Linux3 apps
slackpkg
Open-source Slackware-specific: slackpkg install pkgname fetches and installs .txz packages. Also: installpkg package.txz for local install.
XZ Utils + tar (CLI)
Open-source tar -xf file.txz decompresses and extracts in one command. Both xz and tar are pre-installed on virtually all Linux distros.
Ark / File Roller (GNOME)
Open-source Double-click the .txz in the file manager; GUI archive manager handles it transparently. Technical details
deep spec| Outer compression | LZMA2 via XZ container; optional pre-filters: BCJ (executables), delta (binary data) |
| Inner archive format | TAR - POSIX ustar, GNU tar, or pax interchange format |
| Magic bytes | FD 37 7A 58 5A 00 at offset 0 (standard XZ stream header) |
| Byte order | Little-endian (XZ header fields) |
| Relationship to .tar.xz | .txz is a shortened alias for .tar.xz - identical format, not a separate specification |
| Integrity checking | XZ per-block and stream CRC-64 (default); CRC-32 or SHA-256 selectable; TAR per-header octal checksum |
| Encryption | None built-in; apply GPG externally if needed |
| Slackware packaging | Native package format since Slackware 13.1 (2010); managed by installpkg/removepkg/pkgtool |
| Compression ratio | Better than .tgz (gzip) and .tar.bz2 (bzip2); comparable to .tar.zst at high compression levels |
| Decompression speed | Moderate - faster than compression; slower than gzip/zstd decompression |
| TAR path length limit | 255 bytes (ustar); GNU tar and pax extensions remove this limit |
| Typical size | 50 KB - several GB; Linux kernel source tarballs 100-200 MB compressed |
| Associated OS | Linux, BSD, macOS, Windows (via 7-Zip or WSL tar) |
| Gaining competitor | .tar.zst (Zstandard) gaining adoption for speed-focused use cases; .txz/.tar.xz remains dominant for source releases |
| Released | 2010 (Slackware 13.1 adopted .txz as its native package format; .tar.xz widely used since XZ Utils 5.0, 2010) |
| Latest version | XZ file format 1.0.4 (2009); XZ Utils 5.6.x |
| Open standard | Yes · royalty-free |
| Specification | tukaani.org |
TXZ conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about TXZ files.
Frequently asked questions
What is a .txz file?
How do I open a .txz file on Windows?
What is .txz used for in Slackware Linux?
installpkg or managed with slackpkg.Is .txz the same as .tar.xz?
How do I extract a .txz on Linux?
tar -xf file.txz in a terminal. Both tar and xz are pre-installed on virtually all Linux systems.
