7z
7z is a compressed archive file format that supports several different data compression, encryption and pre-processing algorithms. The 7z format initially appeared as implemented by the 7-Zip archiver. The 7-Zip program is publicly available under the terms of the GNU Lesser General Public License. The LZMA SDK 4.62 was placed in the public domain in December 2008. The latest stable version of 7-Zip and LZMA SDK is version 23.01.
| Filename extension |
.7z |
|---|---|
| Internet media type |
application/x-7z-compressed |
| Uniform Type Identifier (UTI) | org.7-zip.7-zip-archive |
| Magic number | '7', 'z', 0xBC, 0xAF, 0x27, 0x1C |
| Size limitation | 264 bytes (roughly 18 exabytes) |
| Developed by | Igor Pavlov |
| Initial release | 1999 |
| Type of format | Data compression |
| Open format? | Yes: GNU Lesser General Public License / Public domain |
| Website | 7-zip |
The official, informal 7z file format specification is distributed with 7-Zip's source code since 2015. The specification can be found in plain text format in the 'doc' sub-directory of the source code distribution. There have been additional third-party attempts at writing more concrete documentation based on the released code.