15,432 developers used QuickKit today — 100% free, runs entirely in your browser

YAML validator — check YAML syntax online

Validate YAML configuration files and detect indentation errors, duplicate keys, and structural issues with exact line numbers

JSONJavaScriptTypeScriptCSSHTMLYAML
YAML validator
Loading editor…

Ctrl+Enter to validate

YAML-specific

Why validate your YAML?

YAML is famously error-prone. A single wrong indentation level silently moves a key to the wrong parent block, and most YAML parsers either ignore duplicate keys or behave inconsistently. Kubernetes, GitHub Actions, Docker Compose, and Ansible deployments fail silently when YAML is malformed, often with cryptic error messages far from the actual mistake. QuickKit's YAML validator uses the js-yaml parser — the same library used by many Node.js tools — to parse your YAML and report the exact line and column of any syntax error. Duplicate key detection and structural validation are included, making it the fastest way to sanity-check config files before committing.

Questions

Frequently asked questions

This validates YAML syntax (well-formedness). Schema-based validation — checking that values match a specific schema — is separate.
Yes — files with multiple documents separated by --- are fully parsed and each document is validated.
Keep exploring

Related tools

All tools