You do not need WinRAR to open a RAR file on Windows 11
A file arrives as `.rar`, double-clicking does nothing useful, and every search result tells you to install something. Windows 11 has been able to read RAR and 7Z since 23H2 β what usually happens is that an installed archiver took the file association. Here is what actually works, measured, and where it stops working.
If what came out of the archive needs a format change, this does it locally. Nothing is uploaded.
The capability is already there
Windows 11 gained native RAR, 7Z and TAR handling in 23H2. You can confirm it without opening a file: the registry entry for .rar lists ArchiveFolder among its handlers, which is Windows' own archive shell extension.
On the machine used for this write-up, the default for .rar was an installed archiver rather than ArchiveFolder. That is the usual reason people never discover the built-in support: whatever they installed years ago still owns the association. Uninstall it and Windows takes over.
Right-click the archive, Open with, Windows Explorer. If it opens like a folder, the built-in handler is doing the work.
One line from a terminal
Windows ships tar at C:\Windows\System32\tar.exe. It is libarchive underneath, so despite the name it reads RAR and 7Z too.
# Look inside without extracting
tar -tf C:\Users\you\Downloads\archive.rar
# Extract into the current folder
tar -xf C:\Users\you\Downloads\archive.rar
# Extract into a folder you choose
tar -xf archive.7z -C C:\Users\you\Desktop\unpackedMeasured while writing this: a 1,731-byte RAR listed its entry and extracted to 4,585 bytes; a 909KB 7Z extracted all 29 files. Both returned exit code 0, with nothing installed.
The RAR tested carried the signature 52 61 72 21 1A 07 00, which is RAR4. RAR5 β what current WinRAR writes by default β was not tested, because no RAR5 sample was available. That is a gap in the measurement, not a known failure.
Where it stops: creating a RAR
Reading and writing are different problems. The RAR compressor is proprietary, so Windows cannot produce one. The trap is that it does not tell you.
Running tar -a -cf out.rar folder returned exit code 0 and produced a file. That file was 5,837,312 bytes β *larger* than the 5,806,287-byte source. Byte 257 of it reads ustar: it is an uncompressed tar with a .rar name. Nothing warned about it.
Password-protected archives are the other wall. There is nowhere to pass a password. Creating RAR and handling encrypted archives are the two jobs that still justify installing something.
If you are packing, which format
The same tar writes 7Z, ZIP and TAR.GZ correctly β verified by signature, not by extension. Packing one 5,806,287-byte tree three ways:
| Format | Result | vs source | Pick it when |
|---|---|---|---|
| zip | 1,798,875 bytes | 31.0% | The recipient is unknown |
| tar.gz | 1,788,453 bytes | 30.8% | It is going to Linux or a pipeline |
| 7z | 798,214 bytes | 13.7% | Size is what matters |
7z is 2.25x smaller than the zip of the same content β and tar.gz landed within 1% of zip, which surprised me. The tradeoff is reach: zip opens everywhere, 7z does not.
# Smallest
tar -a -cf out.7z -C .\folder .
# Safest to send
tar -a -cf out.zip -C .\folder .FAQ
Q. Does this work on Windows 10?
tar has shipped since Windows 10 1803, but RAR and 7Z reading arrived with Windows 11 23H2. On Windows 10, expect tar and zip only.
Q. Double-clicking opens some other program.
An installed archiver owns the association. Right-click, Open with, Windows Explorer for a one-off; change it permanently under Settings, Apps, Default apps, by file type.
Q. Will it open RAR5?
Not tested here β the sample measured was RAR4. To check your own file, run tar -tf yourfile.rar. If the listing appears, it can be extracted.
Q. What about password-protected archives?
Not supported by this route. There is no way to supply a password, so a dedicated archiver is required.
Q. Why did my .rar come out bigger than the folder?
Because it is not a RAR. Windows cannot write that format, and instead of failing it writes an uncompressed tar with the name you asked for. No compression happened, so it grew.
If what came out of the archive needs a format change, this does it locally. Nothing is uploaded.