{}DevTools Kit

YAML Validator & Converter

Validate YAML and convert between YAML and JSON online. Clear error messages with line numbers, fully client-side and free.

// yamlYAML → JSON○ ready
YAML input
JSON output
Waiting for input — paste YAML to validate.
About this YAML validator & converter
YAML is a human-friendly format for configuration — Kubernetes manifests, CI pipelines, Docker Compose, and app settings. Its whitespace sensitivity makes small mistakes easy to miss. This tool validates YAML and pinpoints the offending line, and converts cleanly between YAML and JSON in both directions.
Everything runs locally in your browser, so it is safe to paste config files containing private values — nothing is uploaded.
How to use it
  1. Pick a direction: YAML → JSON or JSON → YAML.
  2. Paste your document on the left.
  3. The converted result and a valid/invalid status appear instantly.
  4. Copy the output from the right pane.
Frequently asked questions
How does the validator find errors?
It parses your YAML with a full YAML 1.1 parser. If the document is malformed, it reports the reason and the line number of the problem so you can fix it quickly.
Can it convert between YAML and JSON?
Yes. Switch to “YAML → JSON” to turn valid YAML into formatted JSON, or “JSON → YAML” to do the reverse. Validation happens automatically in both directions.
Why did my tabs cause an error?
YAML does not allow tab characters for indentation — only spaces. Replace leading tabs with spaces and the document will parse.
Is my YAML uploaded anywhere?
No. Parsing and conversion run entirely in your browser, so config files and secrets never leave your device.
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