Software & Apps > File Types > What Is an ARJ File? This is a compressed archive that can store other files and folders By Tim Fisher Tim Fisher Senior Vice President & Group General Manager, Tech & Sustainability Emporia State University Tim Fisher has more than 30 years' of professional technology experience. He's been writing about tech for more than two decades and serves as the SVP and General Manager of Lifewire. lifewire's editorial guidelines Updated on March 8, 2023 File Types File Types Apps Windows MS Office Linux Google Drive Backup & Utilities Design Cryptocurrency Close What to Know An ARJ file is an ARJ compressed file.Open one on Windows with PeaZip, or use The Unarchiver on macOS.Convert to ZIP or TAR with Convertio, or extract the files to convert what's inside. This article describes what the ARJ compressed file format is, including how to open an ARJ file and how to convert one to a different archive format. Lifewire / Julie Bang What Is an ARJ File? A file with the ARJ file extension is an ARJ compressed file. Like most archive file types, they're used to store and compress multiple files and folders into one easily manageable file. How to Open an ARJ File ARJ files can be opened with any popular compression/decompression program. We recommend 7-Zip or PeaZip, but there are several free zip/unzip tools to choose from, including the official ARJ32 program. ARJ files that open with PeaZip. If you're on a Mac, try The Unarchiver or Incredible Bee's Archiver. Regardless of the one you choose, any of these types of programs will decompress (extract) the contents of an ARJ file, and some may also have the ability to create one. The RAR app from RARLAB is an option for opening ARJ files on an Android device. How to Convert an ARJ File To convert from ARJ to some other archive format, extract all the contents held in the file and then compress them to a new format using a file compressor from the list mentioned above. For example, instead of looking for an ARJ to ZIP or RAR converter (or whatever format you want it to end up in), it'd be easier and probably quicker to open the archive to detach all its data. Then, just re-make the archive but choose the format you want, like ZIP, RAR, 7Z, etc. There are, however, online ARJ file converters, but since they make you upload the archive online first, they're not very useful if your file is really large. If you have a small one, try Convertio. Upload the file to that website, and you'll be given the option to convert it to a number of formats like 7Z, RAR, TAR, GZ/TGZ, BZ2, or ZIP. For bigger archives, use Filestar. It's a desktop program, so it installs to your computer to not only extract files from the archive, but also convert the whole file to TAR, 7Z, RAR, ZIP, and several other formats (all listed here). Still Can't Open It? Files that don't open with the ARJ openers above are most likely not in this format. The reason you're mistaking your file for an ARJ archive might be if the file extension looks similar, but is really just a letter or two off. For example, ARF and ARD files share the same first two extension letters, but they won't open with the same programs. Was this page helpful? Thanks for letting us know! Get the Latest Tech News Delivered Every Day Subscribe Tell us why! Other Not enough details Hard to understand Submit