WinRAR Compressed Archive

RAR is the archive format of WinRAR. You meet it in downloads from forums and file-sharing sites, in game mods, scanned comics and older software collections, often split into parts such as .part1.rar, .part2.rar. Unlike ZIP, RAR was never an open format: anyone can read it, but only WinRAR and the RAR command-line program made by the same company can create it. That one fact explains most of what people search for about RAR.

History

The Russian programmer Eugene Roshal released RAR in 1993 (the name means Roshal ARchive); WinRAR for Windows followed in 1995. Today the software is sold by win.rar GmbH. In 2013 WinRAR 5.0 introduced a new archive structure, RAR5; the older one has since been called RAR4. RAR5 brought AES-256 encryption instead of AES-128, optional BLAKE2sp checksums and much larger dictionaries. WinRAR 7.0 (2024) raised the dictionary limit to 64 GB; archives with a dictionary over 4 GB can only be unpacked by version 7.0 and newer. The extension stays .rar for both versions, so the file name tells you nothing.

What RAR can do

• Solid compression: files can be compressed as one continuous stream, which helps a lot with many similar files. The price: to extract the last file, everything before it must be decompressed.
• Recovery record: optional redundant data that lets WinRAR repair a damaged archive. This is RAR's real strength over ZIP and 7z.
• Volumes: splitting into parts of fixed size, originally for floppies and CDs, today for upload limits. Old naming used .r00, .r01…, the current one .part1.rar.
• Encryption: optionally including file names, so without the password you cannot even see what is inside.

The format of RAR5 is publicly documented by RARLAB, and the source code of UnRAR may be used freely for extracting. Its licence, however, forbids using it to recreate the compressor. That is why free archivers read RAR but none of them writes it.

How to open a RAR file

Windows 11 (since version 23H2) opens RAR in File Explorer, unless it is encrypted. On Windows 10 and older you need a program: 7-Zip (free) or WinRAR. macOS cannot open RAR on its own; use The Unarchiver or Keka. Linux: unrar x or 7z x; desktop archive managers use them in the background. On Android there is the official RAR app from RARLAB; on iPhone you need a third-party archiver app.

Common problems

"Unexpected end of archive"

The file is incomplete, or it is one part of a multi-volume set and the other parts are missing. All parts must be in the same folder; start extracting from the first one.

"CRC failed" or "checksum error"

The data is damaged. If the archive has a recovery record, WinRAR's "Repair archive" command can fix it. Without one, re-downloading is usually the only option. Re-packing a damaged RAR to another format will not repair it.

"Unsupported compression method" or "unknown format"

An older extractor meets a RAR5 file or an archive from WinRAR 7 with a very large dictionary. Update 7-Zip or WinRAR.

RAR asks for a password

Without the password the content is unreadable. Tools that promise to "remove" the password only try guesses, and with AES-256 that rarely works.

Converting RAR

The typical case is sending files to someone who cannot open RAR: an office PC with Windows 10 and no admin rights, a Mac, a phone. Convert RAR to ZIP and everyone can open it. Other targets are 7z (similar size, open format), TAR or tar.gz for Linux, and ISO. Our converter extracts the RAR (RAR4 and RAR5) and packs the content again; the files themselves stay identical. Encrypted RARs cannot be converted, and neither can split archives, because each file you upload is processed on its own: join or extract the parts first. The limit is 100 MB per upload and 2 GB of unpacked content. The recovery record is not carried over, ZIP and 7z have no equivalent. Converting anything to RAR is not possible with us, for the licensing reason above.

More: RAR format family (Library of Congress), RAR 5.0 technical note (RARLAB).