TAR + 7z (.tar.7z) file format

.tar.7z · archive+compression · introduced 2000 by 7-Zip community

What is a TAR + 7z (.tar.7z) file?

A .tar.7z is a TAR archive packed inside a 7z container. People do this when they want LZMA2 compression but also want the resulting file to preserve full Unix permissions, symlinks, and ownership — features the 7z native format does not always handle perfectly across platforms.

Most readers reach this page after double-clicking a .tar.7z file and finding their operating system unsure what to do with it. The good news: TAR + 7z (.tar.7z) is a well-understood format with mature tooling on every major platform. It is supported in one click by mainstream archivers on Windows, macOS, and Linux.

How to extract a TAR + 7z (.tar.7z) file

Opening a .tar.7z file is straightforward on every modern operating system. The exact steps depend on which platform you are on:

On Windows

Locate the .tar.7z file in File Explorer.
Right-click the file. If you have 7-Zip installed, choose 7-Zip → Extract Here. On Windows 11 the built-in extractor handles ZIP, 7z, RAR and several other formats directly through Extract All…
If prompted, pick a destination folder and click Extract.
The extracted files appear in a folder next to the original archive.

On macOS

Find the .tar.7z file in Finder.
Install The Unarchiver from the Mac App Store, or Keka for both creating and extracting.
Right-click the file → Open With → The Unarchiver (or just double-click after Unarchiver is set as the default).
The extracted folder appears next to the archive.

On Linux

Use your file manager: right-click the archive → Extract Here (file-roller on GNOME, Ark on KDE).
On the command line, run one of:
```
tar -xf archive.tar.7z
```
The files appear in the current directory.

How to create a TAR + 7z (.tar.7z) file

To pack files into a .tar.7z archive, you typically need an archiver that supports writing this format. Not every tool can create every format — for example, only WinRAR can create real RAR files. The sidebar lists the software known to read and write TAR + 7z (.tar.7z).

On the command line, the canonical create command is:

# Use 7-Zip, PeaZip, or the format's reference tool to create .tar.7z files.

If you regularly create archives at scale, a dedicated archive automation suite can wrap this command in scheduled jobs, integrity checks, and offsite replication.

Strengths

LZMA2 compression
Preserves Unix metadata
Solid mode

Weaknesses and limitations

Two-step pipeline
Not random-access

Typical use cases

Cross-platform Unix backups
Maximum compression with permission preservation

Technical details

TAR + 7z (.tar.7z) uses the TAR wrapped in 7z algorithm and is identified on disk by the magic byte sequence 37 7A BC AF 27 1C. The standard MIME type is application/x-7z-compressed. The format is an open specification and is free for any use.

Frequently asked questions

Is TAR + 7z (.tar.7z) safe to open?

Archive files are containers — they are only as safe as what they contain. A .tar.7z from a trusted source is fine; one received from a stranger can hold malicious executables, scripts, or files engineered to exploit bugs in your archiver. Always keep your archiver updated, and never run unknown executables that come out of an archive. A safe workflow is to extract into a sandbox and scan the contents before opening anything.

What is the maximum file size?

POSIX TAR is limited to 8 GB per file in the historical header, but the GNU and PAX extensions raise this to 8 ZB and are universally supported by modern tar implementations.

Can I password-protect a TAR + 7z (.tar.7z)?

Not natively. TAR and the standard Unix compressors do not include encryption. Wrap the archive with GnuPG or age for confidentiality, or use a format like 7z that builds AES-256 in.

How does TAR + 7z (.tar.7z) compare to other formats?

See our format comparison pages such as ZIP vs 7z, ZIP vs RAR, and tar.gz vs tar.xz for side-by-side feature tables.