DevConvertor

YAML Validator

Validate YAML using js-yaml, a real, maintained YAML parser — not a regex approximation. Get an exact line and column for the first syntax error, across nested objects, arrays, multiline strings, and comments.

Validates as you type

ReadyMarkup ToolsFree · No account required

Related tools

YAML FormatterReformat YAML with consistent indentation.YAML to JSONConvert YAML to JSON, preserving types.JSON ValidatorCheck whether JSON is valid, with a precise error location.

Features

  • Real YAML parsing (js-yaml), not a regex approximation
  • Exact line and column for the first syntax error
  • Handles nested objects, arrays, multiline strings, and comments

How to use

  1. Paste the YAML you want to check.
  2. The status banner updates automatically.
  3. If invalid, the message shows what's wrong and exactly where.

FAQ

What counts as valid YAML here?
Anything js-yaml — a real, widely used YAML parser — accepts. This isn't a regex-based approximation, so the same rules that would apply when your code actually loads the file apply here too.
Does it check comments and multiline strings?
Comments are valid YAML syntax and parsed correctly (though they don't appear in the resulting data, since they're not data). Multiline block scalars (| and >) are fully supported.