arj

.arj — ARJ Archive

Robert K. Jung · 1991

Developer

Robert K. Jung

What is a .arj file?

ARJ is a proprietary archive file format developed by Robert K. Jung. It was popular in the DOS era for its good compression ratios and support for splitting large archives into multiple smaller files. While less common today, it can still be encountered.

Programs That Open .arj Files

Platform	Program
Windows	7-Zip	Free
	WinRAR	Paid
	PeaZip	Free
	ARJ Command Line	Free	Official
macOS	The Unarchiver	Free
	PeaZip	Free

Common Problems with .arj Files

⚠️ Cannot open ARJ file

Ensure you have an ARJ-compatible decompression program installed. Try using a modern archiver like 7-Zip or WinRAR.

⚠️ Corrupted ARJ archive

If the archive was corrupted during download or creation, it may be unrecoverable. Try re-downloading or obtaining a fresh copy.

⚠️ ARJ file is part of a multi-volume archive

Make sure all parts of the multi-volume archive (.a01, .a02, etc.) are in the same directory and attempt to open the first file (e.g., .arj or .a01).

Frequently Asked Questions

What is an ARJ file?▼

An ARJ file is an archive file created using the ARJ compression utility, known for its good compression and ability to split large files.

How do I open an ARJ file?▼

You can open ARJ files using various archive software such as 7-Zip, WinRAR, or the original ARJ command-line tool.

Is ARJ still used today?▼

While less common than formats like ZIP or 7z, ARJ files are still encountered, especially in archives from the DOS era or from specific software distributions.

Technical Details

ARJ archives typically start with the hex signature '60 1A'. The format supports various compression methods, including its own proprietary algorithms, and allows for multi-volume archives.

Did You Know?

ARJ was designed to be a more advanced alternative to the popular PKZIP format of its time.

Security Information

ARJ files themselves are not inherently malicious, but like any archive format, they can be used to package and distribute malware. Always scan downloaded ARJ files with reputable antivirus software before opening.