Archive Explorer

← All formats

PYZ (Python zipapp) file format

.pyz · .pyzw  ·  package (ZIP variant)  ·  introduced 2015 by Python community (PEP 441)

What is a PYZ (Python zipapp) file?

A Python zipapp (.pyz) is a ZIP file containing a Python application, optionally prefixed with a #! shebang line. The python interpreter can execute a .pyz directly, just as it can execute a directory. Useful for distributing single-file Python tools without requiring pip install.

Most readers reach this page after double-clicking a .pyz file and finding their operating system unsure what to do with it. The good news: PYZ (Python zipapp) is a well-understood format with mature tooling on every major platform. It is supported in one click by mainstream archivers on Windows, macOS, and Linux.

How to extract a PYZ (Python zipapp) file

Opening a .pyz file is straightforward on every modern operating system. The exact steps depend on which platform you are on:

On Windows

  1. Locate the .pyz file in File Explorer.
  2. Right-click the file. If you have 7-Zip installed, choose 7-Zip → Extract Here. On Windows 11 the built-in extractor handles ZIP, 7z, RAR and several other formats directly through Extract All…
  3. If prompted, pick a destination folder and click Extract.
  4. The extracted files appear in a folder next to the original archive.

On macOS

  1. Find the .pyz file in Finder.
  2. Install The Unarchiver from the Mac App Store, or Keka for both creating and extracting.
  3. Right-click the file → Open With → The Unarchiver (or just double-click after Unarchiver is set as the default).
  4. The extracted folder appears next to the archive.

On Linux

  1. Use your file manager: right-click the archive → Extract Here (file-roller on GNOME, Ark on KDE).
  2. On the command line, run one of: 
    7z x archive.pyz    # works for almost any format
  3. The files appear in the current directory.

How to create a PYZ (Python zipapp) file

To pack files into a .pyz archive, you typically need an archiver that supports writing this format. Not every tool can create every format — for example, only WinRAR can create real RAR files. The sidebar lists the software known to read and write PYZ (Python zipapp).

On the command line, the canonical create command is:

# Use 7-Zip, PeaZip, or the format's reference tool to create .pyz files.

If you regularly create archives at scale, a dedicated archive automation suite can wrap this command in scheduled jobs, integrity checks, and offsite replication.

Strengths

  • Pure ZIP — no extra runtime
  • Self-contained
  • Works with stock Python

Weaknesses and limitations

  • Cannot include native extensions easily
  • No dependency resolution

Typical use cases

  • Single-file Python script distribution
  • Internal tool deployment

Technical details

PYZ (Python zipapp) uses the ZIP/DEFLATE + shebang algorithm and is identified on disk by the magic byte sequence 50 4B 03 04. The standard MIME type is application/zip. The format is an open specification and is free for any use.

Frequently asked questions

Is PYZ (Python zipapp) safe to open?

Archive files are containers — they are only as safe as what they contain. A .pyz from a trusted source is fine; one received from a stranger can hold malicious executables, scripts, or files engineered to exploit bugs in your archiver. Always keep your archiver updated, and never run unknown executables that come out of an archive. A safe workflow is to extract into a sandbox and scan the contents before opening anything.

What is the maximum file size?

Modern ZIP-based formats use the ZIP64 extension to support archives larger than 4 GB and individual files larger than 4 GB, up to 16 EB in theory. Older tooling that does not understand ZIP64 will report a corruption error on such files.

Can I password-protect a PYZ (Python zipapp)?

Some archivers can wrap PYZ (Python zipapp) files in an encrypted container, but the format itself does not always include built-in encryption. Check your archiver's documentation.

How does PYZ (Python zipapp) compare to other formats?

See our format comparison pages such as ZIP vs 7z, ZIP vs RAR, and tar.gz vs tar.xz for side-by-side feature tables.

Related formats