YAML Validator

Instant YAML Syntax Checking

YAML Input

Chars

Bits

Bytes

No Result Yet

Paste YAML and click validate

Invalid YAML

Please provide valid YAML.

Understanding YAML Validation

Catch Syntax Errors

Find indentation mistakes, missing colons, and bad list syntax before they break a deployment.

CI/CD Confidence

Sanity-check a Kubernetes manifest or GitHub Actions workflow file before committing it.

Line-Number Errors

When YAML is invalid, the error message includes the line number so you can jump straight to the problem.

Local Processing

Your configuration data never leaves your browser — validation runs entirely client-side.

Common YAML Syntax Pitfalls

YAML is whitespace-sensitive: mixing tabs and spaces, inconsistent indentation between sibling keys, and forgetting the space after a colon are the most frequent causes of parse errors. This validator uses the same js-yaml parser found in many popular Node.js tools, so a file that passes here will generally parse correctly elsewhere.

Key Takeaways

Instant Feedback: Validation runs the moment you click, with no need to install a linter.
Line Number Included: Error messages point to the specific line where parsing failed, when available.
Client-Side Only: All validation happens locally in your browser — no data is ever sent to a server.

YAML Validator - Check YAML Syntax Online