YAML Validator

How it works

Documentation

Validate YAML 1.2 syntax, multiple documents, duplicate keys, quoted values, multiline strings, anchors and aliases.

Validation and diagnostics

SyntaxDock reports errors with line and column locations so you can jump directly to the affected source.

Semantics-preserving formatting

Formatting uses two-space indentation while preserving comments, document boundaries, directives, anchors and aliases, and multiline string values.

Private by design

Your YAML stays in your browser. Validation and formatting do not upload or store the document.

How to use

Paste YAML or choose an example, then select Validate YAML. Select a diagnostic to focus its line and column. For valid input, Format YAML produces copyable YAML in the Result area; the input remains available for comparison.

Scope and limits

Syntax validation does not verify application-specific fields, resolve file references or contact services named in the document. For configuration schemas and targeted deployment checks, use the Docker Compose Validator or Kubernetes YAML Validator. Formatting cannot repair invalid YAML or determine whether a configuration will work when deployed.