YAML Validator
Validate YAML syntax and format. Detect errors with line numbers and helpful error messages.
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Output
Ready — enter input to start
Frequently Asked Questions
What is YAML Validator used for?
YAML Validator checks YAML syntax and formatting for errors, providing line numbers for any issues found. It helps DevOps engineers catch configuration errors before deployment, developers validate config files for CI/CD pipelines, and anyone working with Kubernetes manifests, Docker Compose, or Ansible playbooks.
What kinds of errors does it detect?
The validator checks for mixed tabs and spaces, invalid characters in keys (like brackets or special symbols), incorrect indentation (YAML requires multiples of 2 spaces), invalid anchor/alias syntax, and structural issues that would prevent parsing.
Why does YAML require spaces for indentation?
YAML uses spaces for indentation because tabs have ambiguous behavior across different editors and systems. The specification explicitly prohibits tabs for indentation, requiring consistent space usage. This ensures YAML files look identical regardless of the editor used.
What are common YAML mistakes to avoid?
Avoid using tabs for indentation, mixing spaces with tabs in the same file, forgetting to quote strings that contain colons or special characters, using inconsistent indentation levels, and including invisible characters like BOMs at the start of files.
Is my data sent to a server?
No. All validation happens locally in your browser. Your YAML files, which may contain sensitive infrastructure configurations, API credentials, or deployment settings, stay completely private on your device.
What keyboard shortcuts are available?
Press Ctrl+Enter (or Cmd+Enter on Mac) while in the input field to quickly validate your YAML. This enables rapid validation during configuration development.