What YAML errors does the validator detect?

The validator catches indentation errors, invalid syntax, duplicate keys, incorrect data types, tab characters (YAML requires spaces), unquoted special characters, and malformed multi-line strings. Each error includes the exact line number.

Can I convert validated YAML to JSON?

Yes. Once your YAML validates successfully, the tool displays the equivalent JSON representation. This is useful for sending YAML configuration data to APIs that expect JSON.

Why does my YAML fail with a tab error?

YAML strictly requires spaces for indentation — tabs are not allowed. Replace all tab characters with spaces (typically 2 spaces per level). Most editors can be configured to insert spaces when you press Tab.

Does it support multi-document YAML?

Yes. YAML files with multiple documents separated by --- (three dashes) are parsed and validated individually. Each document is checked for syntax errors independently.

Can I validate Kubernetes YAML files?

This tool validates YAML syntax, which catches formatting and structure errors in Kubernetes manifests. For Kubernetes-specific schema validation (checking valid API versions, required fields), use kubectl --dry-run after fixing syntax errors here.

Is my YAML data stored anywhere?

No. All validation and formatting happens in your browser. Your YAML configuration data never leaves your device — safe for validating secrets and sensitive configs.

YAML Validator & Formatter Online

How to Validate YAML

Paste your YAML into the input panel and the validator instantly checks for syntax errors. If your YAML is invalid, you get a clear error message with the line number where the problem occurs. Valid YAML is parsed and displayed as formatted JSON so you can verify the data structure. Convert between formats with our JSON to YAML Converter.

Common YAML Errors

The most frequent YAML mistakes include incorrect indentation (tabs instead of spaces), missing colons after keys, unquoted strings containing special characters (:, #, @), and inconsistent spacing. YAML is whitespace-sensitive — even one wrong space breaks your config. Validate your JSON data with our JSON Formatter.

Common Use Cases

Validate Kubernetes manifests, Docker Compose files, GitHub Actions workflows, and Ansible playbooks before deployment. Catch indentation errors in CI/CD configuration files. Convert YAML configs to JSON for API consumption. Schedule tasks with our Cron Expression Generator. All validation runs in your browser — your config data stays private.

YAML Validator

How to Validate YAML

Common YAML Errors

Common Use Cases

Frequently Asked Questions

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