YAML (YAML Ain't Markup Language) is a human-readable data serialization format commonly used for configuration files, CI/CD pipelines (GitHub Actions, Docker Compose), and data exchange.

What are common YAML syntax errors?

The most common YAML errors are incorrect indentation (YAML uses spaces, never tabs), missing colons after keys, improper quoting of special characters, and duplicate keys.

Can I convert YAML to JSON?

Yes. Use the Convert to JSON button above. YAML is a superset of JSON, so most valid YAML converts cleanly to JSON.

What is the difference between YAML and JSON?

Both are data formats. YAML is more human-readable with cleaner syntax for config files. JSON is more universally supported and required by many APIs. YAML supports comments; JSON does not.

Does YAML use tabs or spaces?

YAML only allows spaces for indentation, never tabs. Using tabs is the most common cause of YAML parse errors. Two spaces per indent level is the widely accepted standard.

Free YAML Validator & Formatter Online

Validate YAML with exact line-number errors, normalize indentation, and convert between YAML and JSON — all in your browser with syntax highlighting.

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Frequently Asked Questions

What is YAML?: YAML (YAML Ain't Markup Language) is a human-readable data serialization format commonly used for configuration files, CI/CD pipelines (GitHub Actions, Docker Compose), and data exchange.
What are common YAML syntax errors?: The most common YAML errors are incorrect indentation (YAML uses spaces, never tabs), missing colons after keys, improper quoting of special characters, and duplicate keys.
Can I convert YAML to JSON?: Yes. Use the Convert to JSON button above. YAML is a superset of JSON, so most valid YAML converts cleanly to JSON.
What is the difference between YAML and JSON?: Both are data formats. YAML is more human-readable with cleaner syntax for config files. JSON is more universally supported and required by many APIs. YAML supports comments; JSON does not.
Does YAML use tabs or spaces?: YAML only allows spaces for indentation, never tabs. Using tabs is the most common cause of YAML parse errors. Two spaces per indent level is the widely accepted standard.