Check YAML for syntax errors and style issues

Find YAML syntax errors and style problems such as tabs, trailing spaces, and duplicate keys.

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ToolYAML Lint
Input
Output
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Preview

How it works

The YAML loader parses the document, then a style pass checks indentation consistency, tab characters, trailing spaces, duplicate keys, and document markers. Syntax errors and style findings are reported separately.

  • Spaces are required for block indentation.
  • Separating style from syntax keeps valid-but-fragile files visible.

Worked example

Valid YAML with no issues
Lint a well-formed YAML document. No warnings or errors
Input
											name: Alice
age: 30
roles:
  - admin
  - user
Output
												Valid: yes
Issues: none
Document count: 1

When to use this

Kubernetes, Ansible, and static-site repositories lint YAML before merge.

Edge cases

  • A tab in indentation is flagged even when it appears aligned.
  • Duplicate mapping keys can be accepted by some parsers but are warned here.
  • --- starts another document rather than a literal line.

References