---
id: yamllint
version: "1.38.0"
license: GPL-3.0-or-later
license_treatment: copyleft
maintenance: active
---

# yamllint — A linter for YAML files.

License: copyleft · Maintenance: active · Popularity: top 1,000 on PyPI

## Install

pip install yamllint
uv add yamllint
poetry add yamllint

## Description

yamllint
========

A linter for YAML files.

yamllint does not only check for syntax validity, but for weirdnesses like key
repetition and cosmetic problems such as lines length, trailing spaces,
indentation, etc.

.. image::
   https://github.com/adrienverge/yamllint/actions/workflows/tests.yaml/badge.svg?branch=master
   :target: https://github.com/adrienverge/yamllint/actions/workflows/tests.yaml?query=branch%3Amaster
   :alt: CI tests status
.. image::
   https://coveralls.io/repos/github/adrienverge/yamllint/badge.svg?branch=master
   :target: https://coveralls.io/github/adrienverge/yamllint?branch=master
   :alt: Code coverage status
.. image:: https://readthedocs.org/projects/yamllint/badge/?version=latest
   :target: https://yamllint.readthedocs.io/en/latest/?badge=latest
   :alt: Documentation status

Written in Python.

Documentation
-------------

https://yamllint.readthedocs.io/

Overview
--------

Screenshot
^^^^^^^^^^

.. image:: docs/screenshot.png
   :alt: yamllint screenshot

Installation
^^^^^^^^^^^^

Using pip, the Python package manager:

.. code:: bash

 pip install --user yamllint

yamllint is also packaged for all major operating systems, see...

## AI interpretation — verify before relying

yamllint is a YAML linter that checks syntax validity and enforces style rules like indentation, line length, trailing spaces, and key duplication across YAML files.

Verdict: yamllint is a stable, actively maintained YAML linter in the top 1000 PyPI packages with minimal dependencies and no known vulnerabilities. Its GPL-3.0-or-later copyleft license is appropriate for open-source workflows but requires license review in proprietary contexts.

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