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

7Z vs XZ

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

Convert 7Z → XZ Convert XZ → 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

XZ Compressed

Archives & Compressed

XZ provides very high compression ratio using LZMA2, common in Linux packages.

About XZ 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.

XZ Strengths

Best-in-class compression ratio among mainstream tools.
Streaming-capable — can pipe through network.
Multi-threaded compression available.
Mature on every Linux distribution.
Supports integrity checking (CRC32, CRC64, SHA-256).

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.

XZ Limitations

Slow compression at high levels — 3-5× slower than gzip.
Memory-hungry: xz -9 can need 700+ MB to compress.
2024 supply-chain backdoor damaged trust in the project.
Zstandard outperforms xz at similar ratios with less memory.

Technical Specifications

Specification	7Z	XZ
MIME type	application/x-7z-compressed	application/x-xz
Compression	LZMA, LZMA2, PPMd, Bzip2, DEFLATE	—
Max file size	16 EB (exabytes)	—
Encryption	AES-256 (content + filenames)	—
License	LGPL	—
Extensions	—	.xz, .txz
Algorithm	—	LZMA2
Standard	—	The .xz File Format specification 1.1.0
Integrity checks	—	None, CRC32, CRC64, SHA-256

Typical File Sizes

7Z

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

XZ

Text/source archive 15-25% of original
Linux kernel (.tar.xz) ~125 MB
Firefox source code ~600 MB

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Convert between 7Z and XZ online, free, and without installing anything. Encrypted upload, automatic deletion after 60 minutes.

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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.

7Z is an open-source archive formato de the 7-Zip project. It uses the LZMA2 compressão algorithm which achieves significantly better compressão ratios than ZIP ou RAR, making it ideal para archiving large arquivos e datasets.

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.

7Z arquivos abrir com 7-Zip (free, Windows), PeaZip (cross-platform, grátis), Keka (macOS), e The Unarchiver (macOS). Windows does not natively support 7Z, so third-party software is required.

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.

Use 7Z when máximo compressão is the priority, como software distribution e backups. usar ZIP when the recipient needs to abrir o arquivo sem installing extra software, since ZIP is natively suportado everywhere.