What Is a 7Z File?

This article explains what a 7Z file is and how to open one on your computer to get to the files that are inside. We'll also look at how to convert one to a different archive format like ZIP, ISO, RAR, etc.

What Is a 7Z File?

A file with the 7Z file extension is a 7-Zip compressed file. It's a bit like a folder on your computer, except that it really acts like a file.

Both a folder and a 7Z file can store one or more files, and even other folders. However, unlike folders, this is just a single file with the .7Z extension that serve as a compressed archive of the data.

You'll most likely only see one when you download bundled files from the internet, like computer software programs, picture albums, collections of documents... basically anything that might be downloaded best in a smaller, compressed form.

Some 7Z files are broken up into smaller chunks to make them easier to send or store. They end up with a different file extension, like .7Z.001.

How to Open a 7Z File

If you're on Windows 11, which includes built-in support for 7Z files, just double-click the file to see what's inside.

Otherwise, there are lots of free unzip tools that can handle this format. 7-Zip, created by the makers of the format, is probably your best on Windows. It lets you not only extract (open) but also create your own 7Z files.

p7zip is the command-line version of 7-Zip for Linux.

PeaZip is another favorite that supports extraction from, and compression to, the 7Z format on both Windows and Linux.

For macOS, Keka or The Unarchiver, both free, are two great alternatives for extracting files out of one. Commander One is another option.

Sometimes, even after you've installed a file extractor program, just double-clicking won't open the file. A quick and simple workaround is to right-click the file and then choose to open it in the decompression program.

In 7-Zip, in Windows 11, this can be done via Show more options > 7-Zip > Open archive, which will open the file in 7-Zip File Manager.

There are also lots of free online 7Z file openers that don't require you to download any software at all, and that work on any operating system with a modern web browser. ezyZip, 123apps Archive Extractor, and Unzip-Online are a few examples. These work by having you upload the file to the website for the extraction process, where you can then download individual files out of it.

If you need to open one on a mobile device, free apps like iZip (iOS) and 7Zipper (Android) should work.

How to Open 7Z Part Files

Do you have multiple 7Z files that need to be opened together? If it's been split into different parts, you must join them together in a very specific way to make the original file that you can then extract normally.

For example, maybe you have a part1.7z, part2.7z, part3.7z, etc. This can be confusing because if you open just one of those, you'll likely find another file called something.001, and that pattern continues with each of the other 7Z files.

It's a bit confusing to grasp if you've never dealt with multipart 7Z files, so I suggest you read through these steps at Nexus Mods Wiki for some picture instructions on how to combine them to ultimately get to the content that's stored away in those parts.

How to Convert a 7Z File

Remember that a 7Z file is really just like a folder that contains one or more files. This means you can't convert one to PDF, DOCX, JPG, or any other format like that. A task like that requires the files to first be extracted out of the archive and then individually converted with a different file converter.

Instead, the only other file formats that one can be converted to are other archive formats, like ZIP, RAR, ISO, etc.

The easiest and quickest way to convert a small 7Z file is to use an online service. Zamzar is one in particular that can convert one to a number of other archive formats, like ZIP, TAR, LZH, and CAB.

Two other examples are CloudConvert and ConvertFiles, which are websites that can convert 7Z to RAR for free in your browser, as well as to other formats like TGZ. Like Zamzar, I recommend reserving these sites for smaller 7Z files since you have to upload the whole archive to the site before you can convert it, and then it needs to be downloaded in order to save it.

See these Free File Converters for Occasionally Used Formats for some other websites that can convert one.

If yours is large, or you want to convert 7Z to ISO, then it's probably best to use a dedicated, "offline" compression/decompression program, like IZArc, TUGZip, or Filzip. Another option is to convert the 7Z file with Filestar, which supports a couple dozen export formats.

Still Can't Open It?

If the programs and websites mentioned above weren't enough to open the file, then it's probably not really a 7-Zip compressed file! What's likely is that you've misread the file extension, which is actually very easy to do.

Z7 is one example of a file extension that could easily be misread as a 7Z file. Those are Z-machine Z-code Version 7 files used by a gaming engine, specifically the Z-machine engine for old text adventure games.

I'm sure other examples could be given, but you get the idea. If you don't actually have a 7Z article, then you'll need to restart your research using the file extension you see at the end of the file name.

More Information on 7Z Files

7Z is an open file format under the GNU Lesser General Public License.

The 7Z file format was originally released in 1999. It supports file sizes up to 16 billion GB.

The format doesn't store file system permissions. This means that you can't set the permissions of files, store them in a 7Z file, and expect the same permissions to be retained when you extract them.

AES 256-bit encryption can be used to prevent the files from being opened unless the password is known.

The 7-Zip program lets you choose five compression levels when making a new file, from Fastest to Ultra. You can even choose Store if you'd rather not compress it, which will be quicker to create and extract files for later but will also take up the most storage space.

If you do choose a compression level, you can pick from various compression methods, including LZMA, LZMA2, PPMd, and BZip2. Some other options when using that program to make a 7Z file include picking a different dictionary size, word size, solid block size, number of CPU threads, and more.

Once a 7Z file has been created, you can add new files to it by simply dragging the files into the folder when it's open in 7-Zip (and probably other file compression programs, too).

Visit 7-Zip.org if you're interested in reading the specifics on the format.