7Z vs TAR — Differences, File Size & When to Use Each

7Z vs TAR

A detailed comparison of 7-Zip Archive and TAR Archive — file size, quality, compatibility, and which format to choose for your workflow.

Convert 7Z → TAR Convert TAR → 7Z

7-Zip Archive

Archives & Compressed

7z uses the LZMA2 compression algorithm to achieve significantly better compression ratios than ZIP. It is open-source and supports strong AES-256 encryption.

About 7Z files

TAR

TAR Archive

Archives & Compressed

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.

About TAR files

Strengths Comparison

7Z Strengths

Outstanding compression ratio — typically 20–50% smaller than ZIP, 10–30% smaller than RAR.
Completely free and open source.
AES-256 encryption of both content and filenames.
Supports enormous archives (16 exabytes).
Multi-threaded compression on modern CPUs.

TAR 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

7Z Limitations

Not natively supported on Windows before Windows 11 23H2 or macOS — requires a separate tool.
Slower compression than ZIP (though decompression is fast).
No built-in recovery records like RAR.
Less ubiquitous in email and casual sharing than ZIP.

TAR 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.

Technical Specifications

Specification	7Z	TAR
MIME type	application/x-7z-compressed	application/x-tar
Compression	LZMA, LZMA2, PPMd, Bzip2, DEFLATE	—
Max file size	16 EB (exabytes)	—
Encryption	AES-256 (content + filenames)	—
License	LGPL	—
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)

Typical File Sizes

7Z

Source code archive ~50% smaller than ZIP
Linux distro installer 2–10 GB
Virtual machine disk image 5–40 GB

TAR

1 MB of source files (uncompressed .tar) ~1 MB
Same files as .tar.gz 150-400 KB
Linux kernel source (.tar.xz) ~120 MB

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Frequently Asked Questions

7Z is an open-source archive format from the 7-Zip project. It uses the LZMA2 compression algorithm which achieves significantly better compression ratios than ZIP or RAR, making it ideal for archiving large files and datasets.

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.

7Z files open with 7-Zip (free, Windows), PeaZip (cross-platform, free), Keka (macOS), and The Unarchiver (macOS). Windows does not natively support 7Z, so third-party software is required.

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.

Use 7Z when maximum compression is the priority, such as software distribution and backups. Use ZIP when the recipient needs to open the file without installing extra software, since ZIP is natively supported everywhere.

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.