RAR

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File Format
Name RAR
Ontology
Extension(s) .rar
MIME Type(s) application/vnd.rar, application/x-rar-compressed
PRONOM x-fmt/264, fmt/411, fmt/613
Wikidata ID Q243303
Kaitai Struct Spec rar.ksy
Released 1993

RAR (Roshal Archive) is a compressed archive format used by the compression software RAR and WinRAR. It was originally for DOS, but has been widely used on Windows (as WinRAR) and other platforms.

The developers make the decompression code available for use in other programs and allow its distribution, but with a license provision that "You cannot use the unrar source to re-create the RAR compression algorithm, which is proprietary."

Contents

Discussion

RAR can be considered to be a family of three main file formats:

  • The (obsolete) format used by RAR before v1.50
  • The format associated with RAR v1.50 through v4.x
  • "RAR 5.0" format

Even within one of these classes, there can be significant differences between different RAR versions.

File identification

RAR files made by versions prior to v1.50 start with bytes 52 45 7e 5e.

RAR files associated with versions 1.50 through 4.20 start with 7 signature bytes: 52 61 72 21 1a 07 00.

"RAR 5.0" format starts with 8 signature bytes: 52 61 72 21 1a 07 01 00.

Specifications

Before v1.50:

  • RAR140DC.EXE (self-extracting RAR archive) → technote.doc

v1.50-4.20:

  • wrar420.exe (self-extracting RAR archive) → TechNote.txt

5.0 format:

Various:

Software

Sample files

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