7-Zip is a file compression and extractor software. Was released first time in 1999 by a Russian programmer who created .7z file format for archives. .7z file format is the best extension to reduce file size for a wide range of files (documents, pictures ..) - see our test regarding file size reduction and which format to use.
The program comes with a straightforward interface, is very easy to use and supports all popular archives. You can create 7Z, ZIP,GZIP and a few others (cannot create .rar - only WinRAR can do it) and extract all popular archives such as ZIP, RAR, 7Z, GZIP and more.
The program has a pretty low speed of compression.
Is below average when is extracting archives.
7-Zip is very good at extracting different archive formats, it supports most popular and used ones.
The default archive format is, of course, its native one .7z and is a great format to reduce file size and save space on hard drive.
It supports different compression levels and methods, you can split the archive in multiple parts based on size (useful if you want to burn them on storage devices such as CD, DVD where ther is a limit of maximum file size), protect access to archive's content with a password, create self extracting files (archives with .exe extension) and test archives for errors.
From program's Options you can associate it to open automatically specific file extensions at double or right click, customize right click menu or change the language of interface (multiple languages are supported).
It doesn't have the feature to repair a corrupted archive.
Although .7z is the most useful type of archive to reduce file size, 7-ZIP isn't very good regarding the speed of compressing and decompressing. It has a clean interface and is easy to use, is recommended for occasional use (when you don't work daily with archives or with many files).