Windows 11 extends support for archive formats thanks to an open-source library

Better late than never: Microsoft finally introduced native support for RAR archives earlier this year, just three decades after the format’s official introduction in 1993. Windows 11 development is now progressing at an accelerated pace, therefore support for a whole lot of new (ancient) archive formats is coming soon.

Windows 11 users can now manage RAR archives natively, with no need for third-party software or questionable archive “unpackers.” Windows 11 22H2, the past year’s last major release of the operating system (distributed on September 20, 2022), will soon become even more proficient in managing different kinds of archive files and formats.

Microsoft recently released KB5031455, an optional, feature-rich preview cumulative update for Windows 11, refreshing the list of archive formats natively supported in the OS. Windows 11 22H2 and later versions can now manage files compressed in the following archive types: .rar, .7z, .tar, .tar.gz, .tar.bz2, .tar.zst, .tar.xz, .tgz, .tbz2, .tzst, .txz. Support for password-encrypted archives is not available yet.

Redmond programmers added support for the aforementioned archive files thanks to the libarchive library, an open source project designed to develop a portable, efficient C library that can “read and write streaming archives” in a variety of formats. Libarchive supports additional archive types (Lzh, Xar) that could eventually come to Windows 11 as well.

Being an optional, non-mandatory update, the KB5031455 patch needs to be installed manually by going through the Windows Update settings page on Windows 11 and searching for newly released updates. If everything goes well with “early testers,” the update’s contents should eventually come to the majority of Windows users through the next batch of cumulative patches scheduled for November’s 2023 Patch Tuesday.

The ability to support additional archive types (besides RAR and Zip) was hinted at by Panos Panay, who talked about the upcoming feature in one of his Build blog posts before he departed Microsoft. Windows 11 users can now get improved performance of archive functionality during compression, Panay said in May 2023.

Extended file type support is part of the Moment 4 package, a new feature update for Windows 11 that provides 72 new features and improvements to the cloud/AI-centric OS. KB5031455 features include the “centralized AI assistance” for Windows known as Copilot, an overhauled File Explorer “experience,” a new Microsoft Backup app, a built-in Passkey Manager, and much more. Meanwhile, Windows 10 users can keep using trustworthy third-party archive managers like WinRAR for the foreseeable future.