tar

File format

About TAR Files

TAR Archive

Released 1979 By Unix (AT&T Bell Labs)

TAR is a Unix archive format that bundles files together without compression. It is commonly combined with gzip or bzip2 for compressed archives and is the standard for Linux software distribution.

Family

Archives & Compressed

Extension

.tar

MIME Type

application/x-tar

Can Use As

Input Output

The story

HOW TAR
CAME TO BE.

TAR stands for "tape archive" and the name is not ironic — when the format was added to Unix Seventh Edition in January 1979, tape drives were how you actually archived files. The format is brilliantly simple: concatenate files end-to-end, each prefixed with a 512-byte header describing the filename, permissions, owner, and size. Streaming-friendly by design: you can pipe a tar through a network socket or a tape without ever seeking.

TAR is still the default archive format on every Unix-like system. It does not compress anything by itself, so in practice you almost always pair it with gzip (.tar.gz / .tgz), bzip2 (.tar.bz2), or xz (.tar.xz). Every Linux distribution release, every Docker image layer, every Rust/Go binary release from GitHub is a tarball.

CURIOSITIES &
TRIVIA.

TAR is literally "tape archive" — designed in 1979 for writing files to reel-to-reel magnetic tape.

The format uses 512-byte headers, which is the traditional block size of Unix tape drives.

TAR does not compress — "tarballs" combine TAR with gzip (.tar.gz) or xz (.tar.xz) for compression.

Docker container images are layers of tar archives stacked on top of each other.

A tar file can include symbolic links, device nodes, hard links, and Unix permissions — things ZIP handles poorly.

STRENGTHS &
LIMITATIONS.

Strengths

Streamable — you can tar files straight to a network pipe, no seek needed.
Preserves Unix permissions, ownership, symbolic links, and timestamps.
Universally supported on Unix-like systems.
Simple format — the GNU tar source has been stable for decades.
No compression overhead — pair with gzip/xz/zstd as needed.

Limitations

No built-in compression — plain .tar files are the same size as their contents.
No random access — reading one file requires scanning from the start.
Windows tooling is second-class — PowerShell only added native tar in 2018.
Multiple incompatible header variants (v7, ustar, POSIX, GNU) over the years.

Typical Sizes & Weights

1 MB of source files (uncompressed .tar)

~1 MB

Same files as .tar.gz

150-400 KB

Linux kernel source (.tar.xz)

~120 MB

Technical Specifications

MIME type: application/x-tar
Extension: .tar
Block size: 512 bytes (traditional)
Header variants: v7, ustar, POSIX.1-2001 (pax), GNU
Max filename length: 100 bytes (v7); unlimited (pax extended headers)

CONVERT FROM
TAR

tar zip tar 7z tar gz tar bz2 tar xz tar lzma tar zst tar lz4

CONVERT TO
TAR

7z tar zip tar gz tar bz2 tar rar tar xz tar cab tar tgz tar jar tar war tar lzma tar zst tar lz4 tar cpio tar ar tar apk tar deb tar rpm tar lz tar iso tar dmg tar snap tar

Common Use Cases

Linux software packages, server backups, file bundling.

Popular TAR conversions

The most-requested destinations when starting from TAR.

TAR → ZIP TAR → GZ TAR → BZ2 TAR → XZ TAR → LZMA TAR → ZST

Frequently Asked Questions about TAR

Frequently Asked Questions

TAR (TAR Archive) is an archive format used to bundle multiple files and folders into a single compressed file. The archive preserves the directory structure and typically reduces total size via compression. TAR sits in the archives & compressed family and has specific strengths around compression ratio, speed, or platform support.

7-Zip, WinRAR, The Unarchiver (macOS), and the built-in archive utilities on Windows and macOS open most TAR files. For command-line extraction, 7z, unar, or the format-specific tool handles TAR cleanly. If your extractor does not recognise TAR, convert to ZIP first — ZIP opens on every operating system without extra software.

Upload the TAR to KaijuConverter and pick ZIP, 7Z, TAR.GZ, or RAR as the target. Our pipeline extracts the original archive and re-compresses the contents into the target format. File permissions, timestamps, and directory structure are preserved where both formats support them.

Depends on the goal. ZIP is the universal baseline — every OS extracts it out of the box. Formats like 7Z or TAR.GZ compress better but require specific tools. TAR may win on compression ratio, password support, or OS integration for specific workflows; ZIP wins on raw compatibility.