The short answer
- RAR is a proprietary archive format that compresses and groups one or more files, with optional encryption, recovery records, and split volumes.
- Open a RAR file with WinRAR or another extractor that supports its RAR version. Inspect the listed filenames before extracting, then extract into an isolated directory and do not automatically run any extracted executable. Keep every part of a split archive together. For an encrypted RAR, supply the correct password; without it, protected headers and file data cannot be read.
- Treat unsolicited RAR files as high risk because the container can carry executables or other dangerous payloads. Use an up-to-date, fixed parser and extract into an isolated directory. Displayed names in an archive listing do not guarantee which filenames will be written to disk, so isolation and not automatically running extracted files remain essential. CVE-2025-8088 affected WinRAR for Windows 7.12 and earlier, allowing a crafted archive to exploit path traversal for arbitrary code execution, and was observed in active exploitation. A valid RAR signature identifies the format but does not establish that its contents are safe.
RAR Archive File
RAR, short for Roshal Archive, was created by Eugene Roshal and is WinRAR's native archive format. RAR compression is lossless, so normal extraction does not alter the archived file contents. RAR 5.0 uses variable-length blocks and can include an encryption header, archive and file headers, service headers, recovery data, and an end header.
RAR can be converted by extracting its files and creating a new archive in the target format. File contents remain unchanged after normal lossless extraction, but conversion may discard RAR-specific recovery records, split-volume relationships, service headers, filesystem metadata, or encryption settings when the target format lacks equivalents. Password-protected content cannot be converted without the password.
How to open it
Open a RAR file with WinRAR or another extractor that supports its RAR version. Inspect the listed filenames before extracting, then extract into an isolated directory and do not automatically run any extracted executable. Keep every part of a split archive together. For an encrypted RAR, supply the correct password; without it, protected headers and file data cannot be read.
Open a RAR file with WinRAR or another extractor that supports its RAR version. Inspect the listed filenames before extracting, then extract into an isolated directory and do not automatically run any extracted executable. Keep every part of a split archive together. For an encrypted RAR, supply the correct password; without it, protected headers and file data cannot be read.
RAR can be converted by extracting its files and creating a new archive in the target format. File contents remain unchanged after normal lossless extraction, but conversion may discard RAR-specific recovery records, split-volume relationships, service headers, filesystem metadata, or encryption settings when the target format lacks equivalents. Password-protected content cannot be converted without the password.
File safety
Treat unsolicited RAR files as high risk because the container can carry executables or other dangerous payloads. Use an up-to-date, fixed parser and extract into an isolated directory. Displayed names in an archive listing do not guarantee which filenames will be written to disk, so isolation and not automatically running extracted files remain essential. CVE-2025-8088 affected WinRAR for Windows 7.12 and earlier, allowing a crafted archive to exploit path traversal for arbitrary code execution, and was observed in active exploitation. A valid RAR signature identifies the format but does not establish that its contents are safe.
An unknown sender, a name ending in two extensions, or contents that do not match the extension — check before you open it.
Converting it
RAR can be converted by extracting its files and creating a new archive in the target format. File contents remain unchanged after normal lossless extraction, but conversion may discard RAR-specific recovery records, split-volume relationships, service headers, filesystem metadata, or encryption settings when the target format lacks equivalents. Password-protected content cannot be converted without the password.
Convert a copy, never the original, then compare quality, metadata, and layout against what you started with.
Common questions
What is a RAR file and what is it used for?
A RAR file is a proprietary Roshal Archive container created by Eugene Roshal. It groups and losslessly compresses one or more files and may also use recovery records, split volumes, and encryption.
How do I open and extract a RAR archive?
Use WinRAR or another extractor that supports the archive's RAR version. Review the filenames, extract into an isolated directory, and do not automatically run extracted programs.
How do I open a RAR file on Windows?
WinRAR uses RAR as its native format, and other compatible extractors may also work. Use a current, fixed version, especially for untrusted archives, and extract into an isolated directory.
How do I open a RAR file on a Mac?
Choose an extractor that explicitly supports the file's RAR version. Older tools may support only earlier RAR versions; encrypted archives also require the correct password.
Why will my RAR archive not open or extract?
The extractor may not support that RAR version, the file may be password-protected, or parts of a split archive may be missing. Confirm version support, provide the password, and place all volumes together before retrying.
What is the difference between RAR 5.0 and RAR 4.x?
RAR 4.x has the seven-byte signature 52 61 72 21 1A 07 00, while RAR 5.0 uses 52 61 72 21 1A 07 01 00 and a variable-length block structure. Older tools may not support RAR 5.0.
What can be lost when I convert RAR to ZIP or another archive format?
The extracted file contents can remain unchanged, but recovery records, split-volume relationships, service headers, filesystem metadata, or encryption settings may be lost if the target format has no equivalent.
Is a RAR file safe, or can it contain a virus?
RAR is a container and can carry executables or other dangerous payloads. A valid signature does not prove safety; use an updated parser, isolate extraction, inspect filenames, and do not automatically run extracted files.
How do I extract split RAR volumes?
Keep every volume together and open the set with an extractor that supports split RAR archives. The volume relationship may not survive conversion to a format without an equivalent feature.
How do I open an encrypted RAR file without extraction errors?
Use a compatible reader and enter the correct password. RAR 5.0 can encrypt archive headers and file data with AES-256, so protected contents cannot be read, previewed, or converted without the password.
Can I extract a RAR archive online without installing software?
Browser-side extractors vary in which RAR versions they support because RAR is proprietary. An encrypted archive still requires its password, and every part of a multi-volume set must be present.
Related formats
Sources
RAR 5.0 archive format · RARLAB official format documentation
RAR Archive File Format Family · Library of Congress Sustainability of Digital Formats
Media Types Registry · Internet Assigned Numbers Authority
PRONOM fmt/613: RAR Archive 5.0 · The National Archives (UK) PRONOM registry
NVD CVE-2025-8088 · NIST National Vulnerability Database