Validate YAML

Validate YAML syntax and structure online. Detects indentation errors, unescaped characters, and malformed mappings with exact line, column, and visual code pointer diagnostics.

Private • In-browser processing • Zero server uploads

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How to Use Validate YAML

1
Paste YAML Data
Paste your YAML manifest or configuration into the editor.
2
Review Diagnostics
The validator checks syntax in real time, displaying a detailed breakdown of issues.
3
Fix Highlighted Errors
Use the visual error pointer snippet to quickly correct formatting faults.

Key Features

Precise Error Localization
Pinpoints exact line and column coordinates of syntax and indentation mistakes.
Visual Code Pointer
Highlights the offending line with an ASCII pointer (`^`) for instant debugging.
YAML 1.2 Compliant
Fully validates nested mappings, sequence dashes, flow syntax, and multiline block scalars.
Completely In-Browser
Audits your private Kubernetes, Docker, and CI/CD manifests securely without server transfer.

Common Use Cases

  • Validating Kubernetes YAML manifests before running `kubectl apply`.
  • Checking GitHub Actions workflow `.github/workflows/*.yml` syntax to avoid failed CI pipeline runs.
  • Auditing Docker Compose files for subtle indentation bugs.
  • Troubleshooting OpenAPI / Swagger API specification documents.

Frequently Asked Questions

YAML uses Python-like indentation to define scope and hierarchy. Mixing tabs and spaces or using inconsistent indentation levels will cause parser failure.

No. The official YAML specification strictly forbids tab characters for indentation; only space characters are permitted.

Yes! All validation runs 100% locally in your web browser. No YAML data is ever sent across the network.

Prettify YAML
Reformat and beautify a YAML document with consistent indentation.
YAML to JSON
Convert a YAML document to equivalent JSON format.
JSON to YAML
Convert a JSON document to YAML format.
Validate XML
Check if XML is well-formed and report any parsing errors.
Validate UTF8
Check if a sequence of bytes or text is valid UTF-8 and report any errors.