decompyle3
Python cross-version byte-code decompiler
Decision gist · record as of 2026-08-14
Yes, if you need to decompile Python 3.7+ bytecode and accept the GPLv3 copyleft constraint. The tool is actively maintained, has low install friction, and carries no known vulnerabilities. Be aware that decompilation is imperfect—the author documents numerous known bugs and acknowledges that control-flow detection remains incomplete. Use the --syntax-verify option to validate output, and cross-check results with other decompilers when accuracy is critical.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.7 or 3.8 to run; can only decompile bytecode from Python 3.7 onwards.
- Does not handle obfuscated code, Cython, MicroPython, or Py2EXE executables.
- Low friction installation with three runtime dependencies (click, spark-parser, xdis).
License · maintenance · safety
GPL3 (copyleft) — Licensed under GPLv3 (copyleft). Any derivative work or distribution must also be open-source under GPLv3; proprietary use or closed-source redistribution is not permitted.
last release 2025-10-01 (317 days) · last repo commit 2026-07-21 · 1,269 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 286,099 downloads/mo, #8,049 on PyPI
Alternatives
Verify before relying
pip install decompyle3
decompyle3 compiled-python-file.pyc
For syntax verification:
decompyle3 --syntax-verify compiled-python-file.pyc- Extent of known decompilation bugs and their frequency in real-world bytecode
- Whether decompilation accuracy varies significantly across Python 3.7–3.13 versions
- Performance characteristics when handling large or complex bytecode files
What it is and what it does
Decompyle3 is a native Python decompiler that converts compiled Python bytecode (.pyc and .pyo files) back into human-readable source code. It accepts bytecode from Python 3.7 onwards and is a reworking of the uncompyle6 project, addressing control-flow detection issues by refactoring grammar and adding more specific markers in the instruction stream. The tool runs as a command-line utility and can optionally verify the syntax of decompiled output.
The package depends on click for CLI handling, spark-parser for grammar-based parsing, and xdis for cross-version bytecode disassembly. It is actively maintained and has no known security vulnerabilities. The author acknowledges numerous decompilation bugs exist (as with all CPython decompilers) and notes that as Python optimization increases, decompilation becomes harder; the tool does not currently support obfuscated code, Cython, MicroPython, or Windows EXE extraction.
Use it for
- Recover source code from compiled Python packages when original source is unavailable or lost
- Analyze and audit third-party Python bytecode for security review or reverse-engineering
- Debug compiled Python applications by examining the decompiled bytecode logic
- Extract and study Python code from legacy or archived .pyc files for documentation or migration
- Test and validate decompilation correctness against Python's own test suite
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you need to decompile Python 3.7+ bytecode and accept the GPLv3 copyleft constraint.
The tool is actively maintained, has low install friction, and carries no known vulnerabilities. Be aware that decompilation is imperfect—the author documents numerous known bugs and acknowledges that control-flow detection remains incomplete. Use the --syntax-verify option to validate output, and cross-check results with other decompilers when accuracy is critical.
Install
decompyle3 on PyPI
Before you install
Low friction installation with three runtime dependencies (click, spark-parser, xdis). Active maintenance with recent commits and no known vulnerabilities. Last release was 317 days ago; repository shows ongoing development.
Requires Python 3.7 or 3.8 to run; can only decompile bytecode from Python 3.7 onwards. Does not handle obfuscated code, Cython, MicroPython, or Py2EXE executables.
License in practice
Licensed under GPLv3 (copyleft). Any derivative work or distribution must also be open-source under GPLv3; proprietary use or closed-source redistribution is not permitted.
Quickstart
pip install decompyle3
decompyle3 compiled-python-file.pyc
For syntax verification:
decompyle3 --syntax-verify compiled-python-file.pycVerify before relying
- Extent of known decompilation bugs and their frequency in real-world bytecode
- Whether decompilation accuracy varies significantly across Python 3.7–3.13 versions
- Performance characteristics when handling large or complex bytecode files
Package facts
| License | GPL3 copyleft |
| Python support | Not specified |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 3 packagesclickspark-parserxdis |
| Maintenance | Actively maintained 317 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 286,099 / month, #8,049 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableIntended Audience :: DevelopersLicense :: OSI Approved :: GNU General Public License v3 (GPLv3)Operating System :: OS IndependentProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.7Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9Programming Language :: Python :: Implementation :: PyPyTopic :: Software Development :: DebuggersTopic :: Software Development :: Libraries :: Python Modules |
Evidence: decompyle3-3.9.3-py37-none-any.whl; decompyle3-3.9.3-py38-none-any.whl; decompyle3-3.9.3-py39-none-any.whl; decompyle3-3.9.3-py3-none-any.whl
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See also depyf · uncompyle6 · xdis · pycnite · pyclean · bytecode · ast-decompiler · pyc-wheel · ethereum-dasm · pyinstxtractor-ng