Free online PKG to 7Z converter

People convert PKG archives to 7Z when they need a smaller, broadly supported archive for storage or transfer. The conversion is also useful when an installer package must be inspected as ordinary files instead of preserved as an installable package.

What the PKG format is

In the Archives context, .pkg identifies a software package archive, most commonly a macOS Installer package. macOS packages are typically XAR containers holding metadata, a payload archive, scripts, and installation resources; package-building tools such as Apple’s pkgbuild and installer tools create them. You encounter PKG files when downloading macOS software, distributing internal applications, or storing installation packages.

PKG is not one universal archive specification. A file with this extension can use a package structure that ordinary archive tools only partly support, so inspect the file before choosing a conversion method.

What the 7Z format is

.7z is an archive format implemented by 7-Zip and compatible tools such as p7zip. It supports high compression ratios, solid compression, AES-256 encryption, split volumes, and multiple files or directories in one container. Use it for general-purpose storage, transfer, and backup when the recipient has 7-Zip, PeaZip, Keka, or another 7Z-compatible extractor.

How to convert PKG to 7Z

The reliable method is to extract the PKG contents and create a new 7Z archive. This preserves the files but does not preserve the original package as an installable PKG.

1. Install 7-Zip on Windows, or install a compatible 7z command-line package on macOS or Linux.
2. Test whether the package is readable with 7z l software.pkg.
3. Extract it to a separate directory with 7z x software.pkg -oPKG_contents.
4. Create the 7Z archive with 7z a -t7z software.7z PKG_contents.
5. Verify the result with 7z t software.7z.

For a macOS installer package that 7-Zip cannot open, use Apple’s package utility: pkgutil --expand-full software.pkg PKG_contents. Then create the archive with 7z a -t7z software.7z PKG_contents. On systems with XAR installed, xar -xf software.pkg can also expose the package container before the files are recompressed.

On Windows, the graphical equivalent is to open the PKG with 7-Zip, choose Extract to, select the extracted directory, right-click it, and choose 7-Zip → Add to archive; set Archive format to 7z.

You can also use the free converter on 101convert.com without installing software. Select the PKG file, choose 7Z as the output format, start the conversion, and download the resulting archive.

Compatibility and limitations

Creating a 7Z archive does not convert the contents back into a functional macOS installer. Installer scripts, package metadata, permissions, signatures, and receipt information may not survive extraction and recompression in a form that macOS Installer accepts. Keep the original PKG when installation, code signing, notarization, or package verification is required.

If the goal is only to store the original file inside a 7Z container, use 7z a software.7z software.pkg instead. That embeds the untouched PKG; it does not expose or recompress its internal files.