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Tools / Data & JSON

YAML Validator

Validate YAML 1.2 with duplicate-key checks, detailed line errors, and formatted YAML output entirely in your browser.

Validates YAML 1.2 with unique keys. Duplicate keys, unsupported tags, and aliases are rejected. No YAML is uploaded.

Everything runs locally in your browser.

What is YAML Validator?

YAML is widely used for application configuration, infrastructure manifests and CI workflows. This local validator checks YAML 1.2 syntax and unique keys, reports line and column information, and formats valid documents. For predictable security behavior, this tool does not support custom tags or aliases and is not a Kubernetes- or Docker-specific schema validator.

How to use this tool

  1. Paste a YAML 1.2 document or configuration snippet.
  2. Click Validate YAML to see syntax errors, duplicate keys and unsupported structures.
  3. Copy the normalized YAML or download a .yaml file when validation succeeds.

Example

service:\n name: devtools\n enabled: true

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