flake8
the modular source code checker: pep8 pyflakes and co
Decision gist · record as of 2026-08-14
Yes. Flake8 is a mature, widely-used linter with low install friction, no known vulnerabilities, permissive licensing, and active maintenance. It is the standard choice for Python code quality checking in most projects and CI/CD workflows.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.9 or later.
- Low friction install with three stable runtime dependencies (mccabe, pycodestyle, pyflakes).
- The package is actively maintained with a recent release and no known vulnerabilities.
License · maintenance · safety
MIT (permissive) — MIT license is permissive; you can use, modify, and distribute flake8 freely in commercial and private projects with minimal restrictions.
last release 2025-06-20 (420 days) · last repo commit 2026-07-14 · 3,813 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 58,425,368 downloads/mo, #515 on PyPI
Alternatives
Verify before relying
pip install flake8
flake8 myfile.py- Whether the package's extension system (flake8.extension, flake8.formatting entry points) is stable and well-documented for custom plugins.
What it is and what it does
Flake8 is a wrapper that unifies three separate Python code-checking tools—PyFlakes for logical errors, pycodestyle for style violations, and McCabe for complexity analysis—into a single command-line interface. Instead of running three tools separately, you run flake8 once and get a merged, per-file report of all issues.
The tool is designed for integration into development workflows and CI/CD pipelines. It supports inline directives (# noqa comments) to suppress specific warnings on individual lines or entire files, Git and Mercurial hooks for pre-commit checking, and extensibility through entry points so you can add custom linters or formatters. It has been in production use since its first release in 2010 and is actively maintained.
Use it for
- Enforce PEP 8 style consistency across a Python project in CI/CD pipelines or pre-commit hooks.
- Catch common logical errors (unused imports, undefined names) automatically during code review.
- Identify functions or methods that exceed complexity thresholds to guide refactoring efforts.
- Suppress warnings on specific lines or files using # noqa comments when violations are intentional.
- Extend linting rules with custom plugins via the flake8.extension entry point for project-specific checks.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
Flake8 is a mature, widely-used linter with low install friction, no known vulnerabilities, permissive licensing, and active maintenance. It is the standard choice for Python code quality checking in most projects and CI/CD workflows.
Install
flake8 on PyPI
Before you install
Low friction install with three stable runtime dependencies (mccabe, pycodestyle, pyflakes). The package is actively maintained with a recent release and no known vulnerabilities.
Requires Python 3.9 or later.
License in practice
MIT license is permissive; you can use, modify, and distribute flake8 freely in commercial and private projects with minimal restrictions.
Quickstart
pip install flake8
flake8 myfile.pyVerify before relying
- Whether the package's extension system (flake8.extension, flake8.formatting entry points) is stable and well-documented for custom plugins.
Package facts
| License | MIT permissive |
| Python support | Supports the current Python release >=3.9 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 3 packagesmccabepycodestylepyflakes |
| Maintenance | Actively maintained 420 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 58,425,368 / month, #515 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/StableEnvironment :: ConsoleFramework :: Flake8Intended Audience :: DevelopersLicense :: OSI Approved :: MIT LicenseProgramming Language :: PythonProgramming Language :: Python :: 3Programming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: Implementation :: CPythonProgramming Language :: Python :: Implementation :: PyPyTopic :: Software Development :: Libraries :: Python ModulesTopic :: Software Development :: Quality Assurance |
Evidence: flake8-7.3.0-py2.py3-none-any.whl
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See also flake8-blind-except · flake8-bugbear · flake8-executable · flake8-tuple · mccabe · pyflakes · pylama · pep8-naming · pytest-flake8 · flake8-pyi