TULKIT

YAML Validator - Check YAML Syntax Online

Validate your YAML files instantly with our free online YAML Validator. Detect indentation errors, syntax issues, and formatting problems in your YAML configuration files.

Why Validate Your YAML?

  • Catch Indentation Errors: YAML is whitespace-sensitive
  • Prevent Deployment Failures: Invalid YAML breaks CI/CD pipelines
  • Config Validation: Verify Docker, Kubernetes, and CI configs
  • Precise Errors: Get exact line numbers for issues

Common Use Cases

🐳 Docker Compose

Validate docker-compose.yml before running containers.

☸️ Kubernetes

Check K8s manifests (deployments, services, etc.).

🔄 CI/CD Pipelines

Validate GitHub Actions, GitLab CI, CircleCI configs.

📦 Ansible Playbooks

Check Ansible YAML files for syntax errors.

How to Use This Tool

  1. Paste Your YAML: Enter the YAML content you want to validate.
  2. Click "Validate YAML": Our parser checks your YAML for errors.
  3. Review Results: Fix any issues and re-validate until valid.

💡 Tip: Use spaces (not tabs) for indentation. Most YAML parsers don't support tabs.

YAML Validator Tool

Results will appear here after validation...

YAML Syntax Rules

Valid YAML must follow these rules:

  • Indentation Matters: Use consistent spaces (2 or 4) for nesting
  • No Tabs: Only spaces are allowed for indentation
  • Colon Space: Key-value pairs need space after colon (key: value)
  • Lists: Use hyphen followed by space (- item)
  • Strings: Quotes optional unless containing special characters
  • Comments: Lines starting with # are comments

Common YAML Errors

  • Mixing tabs and spaces for indentation
  • Missing space after colon in key-value pairs
  • Inconsistent indentation levels
  • Unquoted strings with special characters (:, #, etc.)
  • Missing hyphen space in list items

YAML vs JSON

YAML is a superset of JSON, meaning valid JSON is also valid YAML. However, YAML offers additional features like comments, multi-line strings, and anchors/aliases that make it more human-readable for configuration files.

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