WhyCrashed

.7z · application/x-7z-compressed

What is a .7z file?

7-Zip Archive

About the format

A .7z file is an archive in 7-Zip's own format, chosen over ZIP mainly for its compression: LZMA/LZMA2 routinely produces noticeably smaller archives than classic ZIP, which is why big downloads, game mods and dataset dumps favour it. It also supports strong AES-256 encryption with the option to encrypt file NAMES as well as contents (a password-protected 7z can hide even its file listing) and solid compression, which packs similar files together for better ratios at the cost of slower single-file extraction. Windows 11 added native 7z extraction to Explorer in 2023; on anything older, or for creating archives, the free 7-Zip application is the standard answer (it also opens RAR, ISO, CAB and most other archive formats, making it the one archive tool worth installing). Security posture mirrors ZIP exactly: the container is inert, the extracted contents deserve the scrutiny — and password-protected archives from strangers are a scanner-evasion pattern.

How to open a .7z file

Windows

  • Windows 11 Explorer (extract)
  • 7-Zip (full support, free)

macOS

  • Keka, The Unarchiver

Linux

  • 7zip / p7zip

Is a .7z file dangerous?

Same as ZIP — judge the contents, and be wary of password-protected archives from unexpected sources.

Related file types

.zip.rar.iso

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