decompyle3 review

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

decompyle3 is an open-source Python decompiler and bytecode library for developers who need to reconstruct source code from compiled Python files. It translates Python bytecode into equivalent Python source, reads .pyc and .pyo files, and supports fragment decompilation. The project is distributed under the GNU GPL-3.0-or-later license, making it a focused free option for Python bytecode recovery rather than a general-purpose native-code decompiler.

Its strongest fit is a workflow built around Python’s compiled artifacts and command-line processing. decompyle3 provides command-line decompilation tools, syntax verification for decompiled output, and bytecode disassembly capabilities. It can be installed with pip or from source, giving developers two stated installation paths. Fragment support is useful when the available input is not a complete compiled file, while syntax verification adds a direct check on whether the recovered output is syntactically valid.

The main decision point is bytecode coverage. The published project notes say Python 3.7 and 3.8 bytecode has been tested, and that newer Python versions can run the project without enabling decompilation of bytecode greater than 3.8. That makes decompyle3 a sensible choice for recovery work centered on those tested versions, especially when CLI access and disassembly matter. Choose another tool if the requirement is decompilation for later Python bytecode versions or native-code analysis.

decompyle3 pros and cons

• Where it wins
  • Translates Python bytecode into equivalent Python source
  • Handles .pyc, .pyo, and bytecode fragments
  • Includes CLI tools, syntax verification, and disassembly
• Where it doesn't
  • Verified bytecode support is limited to Python 3.7 and 3.8
  • Focused on Python bytecode rather than native-code decompilation
  • No platform or integration details are provided

decompyle3 fact sheet, pricing and score →

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Last updated 7 Oct 2026 · How we research and update