What Is a 7z File?
The basics.
A .7z file (also called "7-Zip archive") is a compressed archive format — like a ZIP or RAR file, but using a compression method called LZMA2 that often achieves smaller file sizes.
Windows and Mac don't natively open .7z files, but free tools handle them effortlessly.
Step-by-Step: Open Your 7z File
Choose your operating system.
Using 7-Zip (Free — Named After This Format!)
Download 7-Zip
Go to 7-zip.org and install the 64-bit version. It's free and takes 30 seconds.
Right-click the .7z file
Find your file in File Explorer, right-click it, and look for 7-Zip in the context menu.
Click "Extract Here" or "Extract to [folder]"
Your files will appear moments later. Enter a password if prompted.
WinZip (opens in new tab) also supports .7z files if you prefer a graphical interface with drag-and-drop.
Using The Unarchiver (Free)
Install The Unarchiver
Free from the Mac App Store. Search "The Unarchiver" and install.
Right-click, Open With, then The Unarchiver
Find the .7z file in Finder, right-click, and choose The Unarchiver.
Done!
Files extract to the same folder. Enter password if prompted.
Keka (free from keka.io) is another great option for .7z files on Mac.
Why Would Someone Send a .7z Instead of .zip?
A fair question.
Better compression. 7z files are often 30–70% smaller than the equivalent ZIP, which matters for very large files.
Stronger encryption. The .7z format supports AES-256 encryption by default, and unlike ZIP files, it can also encrypt the file names.
The trade-off is that .7z isn't as universally supported. But with 7-Zip or The Unarchiver installed, you'll never have trouble with them again.