What is the REV file format?
A .rev file is a WinRAR Recovery Volume - a binary redundancy file created by RARLAB alongside a multi-volume RAR archive set. It contains no compressed files and cannot be extracted; instead it holds Reed-Solomon parity data that WinRAR uses to reconstruct missing or damaged .part volumes.
When a large archive is split into segments such as archive.part1.rar, archive.part2.rar and so on, WinRAR can optionally generate a matching set of .rev files. If one or more .part volumes are later lost or corrupted, WinRAR reads the surviving .rev files and automatically rebuilds the lost volumes - one .rev file recovers exactly one missing part.
Recovery volumes are added at creation time using the rv command-line switch:
rar a -rv3 archive.rar
adds three recovery volumes. In the WinRAR GUI, the equivalent is the Add recovery volumes option in the archive dialog.
Internally, .rev files carry the same RAR file signature (52 61 72 21 1A 07, i.e. Rar! 1A 07) as ordinary archive volumes, but their internal service header identifies them as recovery blocks rather than data blocks. Parity data is stored uncompressed, and each .rev file is exactly as large as one regular .part volume.
The format is conceptually similar to PAR2 parity files used in Usenet recovery workflows, but .rev is a proprietary, RAR-native mechanism supported only by RARLAB tools. A .rev file is entirely useless on its own - it has meaning only alongside the multi-volume set it was built for.
Security & safety
RISK: LOWA .rev file contains only parity data - there is no executable code and nothing to run, so the format itself is harmless. The only caution is the usual one for RAR sets from untrusted sources: once you reconstruct and extract the archive, scan the extracted files before opening them, because the archive payload (not the .rev) could contain malware.
Format details
in a nutshell- TortoiseSVN / Subversion 'Revisions' - Some tools label exported revision data with .rev, unrelated to RAR recovery volumes.
- C64/retro emulator REV files - A few legacy emulators and tools use .rev for revision/region data; niche and unrelated.
Programs that open REV files
Windows1 app
WinRAR
Paid Put all .rar parts + .rev files in one folder, then Tools > Repair archive (or just extract the .part1.rar) - WinRAR uses the .rev files to rebuild missing parts. 
macOS1 app
RAR for macOS (RARLAB CLI)
Paid In Terminal run 'rar rc archive' (recover) with the .rar and .rev files present to reconstruct the set. 
Linux1 app
rar / unrar (RARLAB)
Free Run 'rar rc archive' with all parts and .rev files in the directory to recover missing volumes, then extract. 
Android1 app
RAR (RARLAB)
Free Open the folder containing the parts and .rev files; the app can repair/extract the set. Technical details
deep spec| File type | Binary Reed-Solomon parity (recovery) volume for a multi-part RAR archive set |
| Byte order | Little-endian |
| File signature (magic bytes) | 52 61 72 21 1A 07 at offset 0 - the standard RAR marker block shared with all RAR volumes |
| RAR4 vs RAR5 distinction | RAR4 recovery volumes end the signature with 07 00; RAR5 recovery volumes use 07 01 00 |
| Parity algorithm | Reed-Solomon error-correction codes |
| Recovery capacity | One .rev file reconstructs exactly one missing or corrupted .part volume; N recovery volumes recover up to N lost parts |
| File size | Equal to the size of one regular .part volume in the set |
| Compression | None - parity data is stored uncompressed inside the recovery volume |
| Encryption | None within the .rev file itself; designed to protect multi-volume sets that may themselves be encrypted |
| Naming convention | archivename.partN.partM.rev (e.g. backup.part1.part3.rev), numbered to indicate which volumes they protect |
| Command-line creation | rar a -rvN archivename.rar - where N is the number of recovery volumes to generate |
| Internal structure | RAR marker block → recovery-volume service header → Reed-Solomon parity data blocks |
| Supported platforms | Windows (WinRAR GUI and CLI), macOS and Linux (rar/unrar CLI), Android (RAR app by RARLAB) |
| Role in archive set | Supplementary redundancy file - has no value in isolation and cannot substitute for the .part volumes it protects |
| Open-format counterpart | PAR2 serves a similar purpose for non-RAR archive sets, particularly in Usenet recovery workflows |
| Released | WinRAR 3.x (recovery volumes; greatly improved in WinRAR 3.80, 2008) |
| Latest version | Recovery volumes for RAR5 archives (WinRAR 5.0+, 2013) |
| Specification | www.rarlab.com |
REV conversions
Community Q&A
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