YAML Validator Online

Validate YAML syntax with real-time error detection. Catches indentation errors, tab usage, and duplicate keys.

How to Use

  1. 1

    Paste YAML

    Paste your YAML configuration or data.

  2. 2

    Validate

    Validation runs in real-time as you paste.

  3. 3

    See errors

    Errors show the line number and description.

FAQ

What are the most common YAML errors?

Tabs instead of spaces (YAML requires spaces only), inconsistent indentation, unquoted strings with special characters (: { } [ ] > | * &), duplicate keys, and incorrect multi-line string syntax.

Can YAML have comments?

Yes. YAML supports single-line comments starting with #. Unlike JSON, YAML allows comments anywhere in the document. Comments run from # to the end of the line.