About YAML Validator

Validate your YAML documents instantly with our free online YAML validator. Check syntax, detect errors with line numbers, and ensure your YAML is well-formed. Perfect for developers working with Docker Compose, Kubernetes manifests, GitHub Actions, Ansible playbooks, and CI/CD configurations. All processing happens client-side — your data never leaves your device.

Features

Pure Client-Side: No data sent to any server. Your YAML stays private.
File Upload & Drag-Drop: Upload .yaml, .yml, or .txt files directly.
Detailed Error Messages: Clear error messages with exact line numbers when validation fails.
Document Statistics: See key count, arrays, objects, and document size at a glance.
One-Click Actions: Copy validation report to clipboard or download as a text file.
YAML 1.2 Support: Handles anchors, aliases, and all standard YAML types.

How to Use

Paste your YAML into the input area, or drag & drop a file.
Click Validate YAML.
Review the validation result — green for valid, red for errors.
Copy or download the validation report if needed.

Common Use Cases

CI/CD Configs: Validate GitHub Actions, GitLab CI, or Docker Compose YAML before deployment.
Kubernetes: Check K8s manifest YAML for syntax errors before applying.
Ansible: Ensure playbook YAML is well-formed before running.
API Specs: Validate OpenAPI/Swagger YAML definitions.

FAQ

Is this tool free?

Yes, 100% free. No sign-up, no limits.

Is my data private?

Absolutely. All validation happens in your browser. We never see your data.

What YAML versions are supported?

We support YAML 1.2 via the js-yaml library, handling anchors, aliases, and all standard types.

How are errors reported?

Errors include the exact line number and a descriptive message so you can quickly locate and fix issues.

YAML-Validator

About YAML Validator

Features

How to Use

Common Use Cases

FAQ

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