YAML Formatter and Validator Online
Paste YAML, catch parse errors, format the document, and copy clean output without sending data to a server.
A YAML formatter parses YAML and rewrites it into readable, consistently indented output.
A YAML validator catches syntax issues such as broken indentation, invalid mappings, and malformed lists.
Watch indentation
YAML is indentation-sensitive, so spaces and nesting levels matter more than they do in JSON.
Use syntax validation first
This page checks YAML syntax, while product-specific schemas need their own validators.
Example
Use it for config files, CI snippets, front matter, and API examples.
Assumption
Formatted output uses two-space indentation and readable line wrapping.
Limitation
Schema-specific validation is not included; the tool checks YAML syntax and formatting.
Config files
Format and check app, tooling, and local service configuration snippets.
CI workflows
Catch YAML syntax issues in workflow examples before opening a product-specific validator.
Front matter
Clean up Markdown front matter for docs, blogs, and static-site content.
API examples
Format YAML request examples and OpenAPI-style snippets for readability.
Does it validate YAML syntax?
Yes. Invalid YAML shows parser errors in the output panel.
Does it validate Kubernetes or GitHub Actions schemas?
No. It validates YAML syntax, not product-specific schemas.
Can I format private config?
Yes. The parser runs in your browser.
Can I use anchors and aliases?
Yes, standard YAML features are handled by the parser where supported.
Suggested workflow
Config review path
Format config text, compare changes, and clean supporting lists before copying a final snippet.