General Information

The main features of 7-Zip

Notes from this site

Not part of the 7-Zip manual. Written by this site; examples checked with 7-Zip 26.04.

Which format should I choose?

Goal	Format	Create	Extract
Smallest file	7z	`7z a a.7z dir/`	`7z x a.7z -oOUT`
Encrypted, names hidden	7z	`7z a -p -mhe=on a.7z dir/`	`7z x a.7z -oOUT` (asks for the password)
Recipient may not have 7-Zip	zip	`7z a -tzip a.zip dir/`	`7z x a.zip -oOUT`
Linux or tar tools	tar.gz or tar.xz	see below	see below

The default format is 7z. gzip, xz and bzip2 hold one stream, so a folder needs a tar first. On Linux and macOS the official console program is 7zz. Zip keeps file names visible even with a password. Free to use in a company; no registration or payment (the manual's FAQ, license).

tar.gz and tar.xz in one command

7z a -ttar -so dummy.tar dir/ | 7z a -tgzip -si dir.tar.gz   # create .tar.gz
7z a -ttar -so dummy.tar dir/ | 7z a -txz -si dir.tar.xz     # create .tar.xz
7z x dir.tar.gz -so | 7z x -si -ttar -oOUT                   # extract either one
tar czf dir.tar.gz dir/                                      # system tar: keeps owner and group

With -so the first name (dummy.tar) is only a placeholder. Without -so, 7-Zip takes dir/ as the archive name and adds the current folder instead (tested). Two-step version: supported formats. See -so.

Permissions and links

In a macOS test, tar, zip and 7z archives all restored permission bits (a mode 755 script stayed executable, a 600 file stayed 600). A symbolic link is stored as a copy of its target unless you add -snl, which the manual lists for tar and WIM only. Owner and group were not kept: the tar listing showed User ID 0 and no names. For Linux backups where owner and group matter, use your system's tar czf; 7-Zip is fine when permission bits are enough. Test a restore either way.

Supported formats: what can be created and what is read-only
7z format: methods and AES-256 encryption
FAQ and start page

General Information

The main features of 7-Zip

See Also