.rar File Extension
.rar archive is, how to open and extract it safely, how Poly supports it, and when ZIP or 7z may be a better choice. File extension details for .rar
Storage Only| File type | RAR compressed archive |
|---|---|
| MIME type | |
| Encoding | Binary RAR archive, optionally compressed and encrypted |
| Operating systems | Windows, macOS, Linux, Android |
| Opens with | WinRAR, RAR, 7-Zip |
| Poly support | Yes. Poly stores, syncs, shares, versions, and downloads RAR archives. |
| Indexed by Poly | Partial. Poly indexes the filename and ordinary file properties, not archived members. |
| Preview in Poly | No. Download the archive to list or extract its contents. |
| Poly agent | No. The Poly agent cannot read files packed inside the archive. |
What kind of file is a .rar?
A .rar file is a RAR archive that bundles one or more files and folders. It can compress related files together, split a large archive across volumes, store recovery data, and protect data and filenames with a password. Its registered MIME type is application/vnd.rar.12
RAR 4.x archives begin with 52 61 72 21 1A 07 00. RAR 5.0 uses 52 61 72 21 1A 07 01 00.3 The bytes start with ASCII Rar!. Self-extracting archives can place an executable stub before this signature, so a trusted archive utility should validate the complete file.
backup.zip to backup.rar does not convert it. ZIP and RAR have different container structures. Extract and repack the files when you genuinely need another format.How do I open a .rar on my computer?
- On Windows, use WinRAR or 7-Zip. WinRAR creates and extracts RAR archives; 7-Zip supports RAR extraction but not creation.24
- On macOS or Linux, use RARLAB's command-line RAR build, 7-Zip, or a compatible desktop archive manager.5
- On Android, use RAR from RARLAB or another trusted archive utility.5
List or test an unfamiliar archive before extracting it. Current split sets commonly use names such as backup.part1.rar, backup.part2.rar, and so on. Keep every part together and start with the first one. Older sets may use .r00 through .r99 for later volumes.12
Poly support for .rar
Poly recognizes .rar as a RAR archive and keeps it stored, synced, shared, versioned, downloadable, and searchable by filename. Poly does not decompress the archive, index its member names or contents, create a thumbnail, or provide an in-app archive browser. The Poly agent cannot inspect files while they remain packed inside it.
Download and extract the archive with a trusted utility when you need its contents. Adding the extracted files to Poly individually gives each one the preview, search, and agent features available for its own format.
History of .rar
Eugene Roshal has described himself as the developer of RAR and WinRAR since 1993.6 The format remains proprietary. RARLAB publishes the RAR 5.0 container description and UnRAR source for decompression, but its license does not permit using that source to recreate the proprietary RAR compression algorithm.37
IANA registered application/vnd.rar in July 2016. The older application/x-rar-compressed label is a deprecated alias that still appears in some software and servers.1
Working with .rar and alternatives
Choose an archive format based on the recipient and workflow:
| Format | Best fit | Main tradeoff |
|---|---|---|
| RAR | Existing RAR workflows, split volumes, recovery records | Creation is tied closely to proprietary RAR tooling |
| ZIP | Broad sharing and built-in desktop support | Does not preserve RAR-specific recovery or volume settings |
| 7z | Compact archives with an openly documented container | Fewer built-in openers than ZIP |
Converting RAR to ZIP or 7z means extracting the members and creating a new archive. The new file may not preserve recovery records, comments, encryption settings, volume layout, file-system metadata, or exact compressed bytes. Keep the original when those details matter.
Footnotes
- Internet Assigned Numbers Authority. application/vnd.rar Media Type Registration. The registration documents the canonical type, deprecated alias,
.rarextension, RAR 4.x signature, and legacy volume names. ↩ ↩2 ↩3 - RARLAB. What Is a RAR File?. The first-party overview covers containers, extraction, multi-volume naming, solid compression, and recovery records. ↩ ↩2 ↩3
- RARLAB. RAR 5.0 Archive Format. The technical note documents signatures, self-extracting archives, volumes, metadata, and encryption. ↩ ↩2
- 7-Zip. 7-Zip. The official feature list includes RAR among unpack-only formats. ↩
- RARLAB. RAR and WinRAR Downloads. The official download page lists graphical and command-line builds by operating system. ↩ ↩2
- Eugene Roshal. About a Supposed WinRAR SFX Vulnerability: Part 2. Roshal identifies himself as the RAR and WinRAR developer since 1993. ↩
- RARLAB. RAR and WinRAR End User License Agreement. The license describes restrictions on recreating the RAR compression algorithm. ↩