About The YAML Formatter and Validator

The YAML Formatter and Validator checks YAML syntax, formats readable YAML, or emits compact flow-style output. It is useful for config snippets, CI files, Docker Compose fragments, Kubernetes examples, static-site front matter, and API tooling that uses YAML.

The tool runs in your browser using the YAML parser loaded on this page. It checks whether the YAML can be parsed, but it does not validate whether the document matches a Kubernetes schema, OpenAPI schema, CI provider schema, or any other product-specific rules.

How to Format YAML Online

1. Paste YAML into the YAML input area.
2. Click Validate to check whether the YAML parses cleanly.
3. Click Format to dump the YAML with readable indentation.
4. Click Minify when you need compact flow-style YAML.
5. Use Load sample to see a realistic service config example.

Choosing Actions Correctly

Validate:
Use this when you only need parser feedback before pasting YAML into another tool or workflow.

Format:
Use this for reviewing nested config, cleaning copied snippets, or making YAML easier to read in tickets and docs.

Minify:
Use this only for compact snippets. Most real-world YAML files are easier to maintain in formatted block style.

Common Use Cases

• Check copied CI, deployment, or app config snippets before editing them further.
• Clean up YAML examples for documentation or issue comments.
• Confirm parser errors include a useful line and column before debugging indentation.
• Normalize a small YAML sample before converting or comparing it elsewhere.

Quick FAQ

Why does YAML fail when it looks visually aligned?
Tabs, mixed indentation, invisible characters, and ambiguous colons can break YAML even when it appears aligned.

Does this validate Kubernetes or OpenAPI rules?
No. It validates YAML syntax, not the meaning of Kubernetes manifests, OpenAPI schemas, or app-specific configuration.

Should I paste production config here?
Avoid configs that contain secrets, credentials, private endpoints, or customer details.

Why can YAML change after formatting?
Comments, anchors, quoting style, and key order may not be preserved by every parser or formatter.