Good news: You may not have to download 7-zip or WinRar anymore, unless you really want to (or like to password-protect files).
In a new cumulative update, Microsoft added support for five new file archive types: .tar, .tar.gz, .tar.bz2, .tar.zst, .tar.xz, .tgz, .tbz2, .tzst, .txz, .rar, and .7z files, BleepingComputer reports. It's worth noting that while 11 extensions are listed here, some are duplicates. For instance, .tar.gz and .tgz use the same archive algorithm; the only difference is the extension given.
While Windows could already handle ZIP files, it didn't work with .7z (7-Zip) archives or .rar files. For those, you still needed to download 7-Zip or WinRar. Those two archive types are abundantly popular, even to this day, so they often require additional downloads. Overall, it's good news, as one common malware vector is fake 7-zip and WinRar apps, often spread through hijacked ad listings in search engine results, or to exploit flaws in the programs directly. With support for new file types, you may not need the additional software anymore.
"May not" being the key words, though, as there is a large omission in this update. Windows 11 can only work these new file archives if they aren't password protected. If they are, then you'll need the software to unlock the files. So make sure you're downloading the legitimate software from the original makers.
Microsoft gave all the details in its KB5031455 Preview cumulative update notes, but don't expect the new feature to appear on your PC automatically. KB5031455 is an optional update, and you have to go out of your way to get it. That's easy enough, though. Just open the Settings app, navigate to Windows Update, and click "Check for Updates." That'll force Windows 11 to see any optional updates you may want to install.