Difference Between unrar and unrar-free on Linux

Extracting RAR archives on Linux typically involves choosing between two packages: unrar and unrar-free. While both utilities serve the primary function of decompressing .rar files from the command line, they differ significantly in licensing, repository placement, and, most importantly, archive format compatibility. This guide breaks down the core differences between the two packages to help you determine which one to install on your Linux system.

Licensing and Repositories

The fundamental reason both packages exist is software licensing.

  • unrar is proprietary freeware provided directly by RARLAB (the creators of the RAR format). Although RARLAB releases the source code for the extraction utility, its custom license explicitly forbids using the code to reverse-engineer the proprietary RAR compression algorithm. Because of this restriction, Linux distributions like Debian and Ubuntu classify unrar as non-free software and place it in restricted repositories (non-free on Debian, multiverse on Ubuntu).
  • unrar-free is a completely free and open-source project licensed under the GNU General Public License (GPL). It was created to provide a version of the tool that adheres strictly to free software guidelines, allowing it to be included in the default, open-source repositories of Linux distributions.

Archive Compatibility and Features

Compatibility is where the practical difference between the two utilities becomes critical:

  • Archive Versions: Modern RAR archives generally use the RAR4 or RAR5 format. The proprietary unrar utility supports every version of the format, including RAR5. In contrast, unrar-free relies on an older, reverse-engineered library that primarily handles legacy RAR formats (versions 1.x and 2.x). If you attempt to unpack a modern RAR4 or RAR5 archive with unrar-free, the operation will fail with an error stating the archive format is unsupported.
  • Advanced Features: The proprietary unrar supports complex archive features seamlessly, including multi-volume (split) archives, password-protected files, file repair, and modern encryption standards. unrar-free lacks consistent support for these advanced capabilities.

Which One Should You Use?

For everyday Linux use, unrar is the recommended choice. Because the vast majority of .rar files encountered today are compressed using modern RAR4 or RAR5 algorithms, unrar-free will fail to extract most files you download.

If you strictly require completely free and open-source software on your system, unrar-free is generally not a viable replacement for modern archives. Instead, consider using unar (The Unarchiver command-line tool) or modern builds of 7z (from the 7zip package), both of which are open-source and capable of extracting modern RAR formats.