7z

File Format
Name	7z
Ontology	Electronic File Formats Archiving 7z
Extension(s)	.7z
MIME Type(s)	application/x-7z-compressed
PRONOM	fmt/484

7z is a file format for archiving and data compression, developed by Igor Pavlov. It is the native format of the 7-Zip archiving application.

Format details

7z supports several compression schemes:

• LZMA (the default for 7-Zip prior to 9.30 alpha)
• LZMA2 (the default for 7-Zip 9.30 alpha +)
• PPMd
• BCJ
• BCJ2
• bzip2
• DEFLATE

Identification

7z files begin with signature bytes '7' 'z' BC AF 27 1C.

The 7-Zip software will automatically find embedded 7z data in many cases (but apparently not if the file extension is .7z). This makes it possible to create hybrid files that look like some other format, but which will be interpreted as 7z format by 7-Zip.

Related formats

• S7z
• UFA (predecessor?)
• 777 (predecessor?)
• BIX (predecessor?)
• ARG (same author)

Specifications

• Refer to the DOC/7zFormat.txt file in the source distribution
  • 7zFormat.txt

Software

• 7-Zip
• 7zX for Mac
• p7zip

Sample files

• https://telparia.com/fileFormatSamples/archive/7z/

Links

• 7-Zip page about 7z Format
• Wikipedia article