YAML Validator

Validate YAML configuration files for syntax errors, indentation issues, and structural problems.

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Validation Checks:

  • Consistent indentation (multiples of 2)
  • Proper key-value pair format
  • Valid list item syntax
  • Matching quotes and brackets
  • Proper nesting hierarchy

How to Validate YAML Online

  1. 1. Paste your YAML content into the input field
  2. 2. Click \"Validate YAML\" to check for errors
  3. 3. Review errors and warnings with line numbers
  4. 4. Fix identified issues in your YAML file
  5. 5. Revalidate until no errors remain

Validation Checks

  • Indentation consistency (multiples of 2)
  • Key-value pair format validation
  • Proper list item syntax
  • Quote matching and escaping
  • Nesting hierarchy verification

Frequently Asked Questions

How do I validate YAML syntax online for free?

Paste your YAML code into the validator and click "Validate". The tool checks for syntax errors, indentation problems, improper key-value formatting, and structural issues. Error messages show line numbers and specific problems to fix.

Why is my YAML file failing validation?

Common causes: mixing tabs and spaces (use only spaces), inconsistent indentation levels, missing colons after keys, improper quotes, incorrect list syntax (- items), or special characters without quotes. The validator identifies the exact line and issue.

Can I validate Docker Compose YAML files?

Yes! The validator checks Docker Compose file syntax. It catches common errors like incorrect indentation, service definition problems, and invalid YAML structure. For Docker-specific schema validation, also use 'docker-compose config' command.

What's the difference between tabs and spaces in YAML?

YAML forbids tabs - you must use spaces only. Tabs will cause validation errors. Use 2 spaces per indentation level (YAML standard). Most YAML errors come from accidental tabs or mixing tabs with spaces. The validator detects these issues.

Can this validator check Kubernetes manifests?

Yes, it validates Kubernetes YAML syntax including deployments, services, config maps, and other manifests. The tool catches structural errors before you run kubectl apply. For full Kubernetes schema validation, use kubectl with --dry-run.

Does this work with Ansible YAML playbooks?

Yes! Ansible playbooks are YAML, so this validator checks syntax, indentation, and structure. It catches errors before you run ansible-playbook, saving debugging time. The tool validates basic YAML structure; ansible-playbook --syntax-check validates Ansible-specific syntax.

About YAML Validator

YAML is sensitive to syntax and indentation errors. This validator helps catch issues before they cause deployment failures or configuration problems.

  • • Prevent configuration errors before deployment
  • • Essential for DevOps and CI/CD pipelines
  • • Works with Kubernetes, Terraform, Ansible
  • • Catch indentation and syntax issues early
  • • 100% client-side - your configs stay private