RAR file format
Roshal Archive
RAR is the WinRAR archive format. It compresses well and supports recovery records, but creating RAR files requires WinRAR — and many devices need an app to open it.
| Property | RAR |
|---|---|
| File extensions | .rar |
| MIME type | application/vnd.rar |
| Introduced | 1993 by Eugene Roshal (WinRAR) |
| Compression method | Proprietary RAR algorithm |
| Password protection | Yes (AES-256 in RAR5) |
| Open source format | No (free to extract, not to create) |
| Built into Windows / macOS | Windows 11 (since 2023 update); macOS needs an app |
| Best for | Large downloads, split archives, recovery records |
What is a RAR file?
RAR (Roshal ARchive) was created by Eugene Roshal in 1993 and is used by WinRAR. RAR5, introduced in 2013, added AES-256 encryption and larger dictionaries. Anyone may write software to extract RAR files, but the compression algorithm is proprietary, so only WinRAR creates them.
Strengths and weaknesses
RAR compresses better than ZIP, can split archives into parts and add recovery records that repair damage. But older Windows versions, macOS, iPhones and many Android phones need a third-party app to open RAR — so converting to ZIP is often the simplest fix.