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SmaftyTools

YAML Formatter

Format and validate YAML, or convert between YAML and JSON. Free online YAML formatter for configs, pipelines and Kubernetes files.

YAML output

Output will appear here

About YAML Formatter

The YAML Formatter validates and reformats YAML with consistent indentation, and converts in both directions between YAML and JSON. It's built for the files you actually touch: Kubernetes manifests, CI pipelines, Docker Compose files and app configs.

YAML's whitespace sensitivity makes it easy to break — a single misaligned space can take down a deployment. Paste your file to validate it instantly and get a clear error message if something's wrong. The converters help when a tool wants JSON but your source is YAML, or vice versa.

Parsing happens locally in your browser, so infrastructure configs stay private.

How to Use the YAML Formatter

  1. Pick a mode: Format YAML, YAML → JSON, or JSON → YAML.
  2. Paste your document into the input pane.
  3. Fix any reported syntax errors, then copy the formatted result.

Features

  • YAML validation with clear, specific error messages
  • Consistent re-indentation of messy YAML
  • Two-way YAML ↔ JSON conversion
  • Handles anchors, multi-line strings and nested structures

Frequently Asked Questions

Why does my YAML fail to parse?

The usual causes are inconsistent indentation (tabs are not allowed), a missing space after a colon, or unquoted special characters. The error message points at the offending line.

Is YAML a superset of JSON?

Effectively yes — valid JSON is valid YAML, which is why the JSON → YAML conversion always works. The reverse needs conversion because YAML's syntax (indentation, anchors) doesn't exist in JSON.

Is the YAML Formatter free?

Yes, the YAML Formatter is completely free with no usage limits. No signup, no account and no installation required.

Is my data safe?

Yes. All processing happens locally in your browser using JavaScript — nothing you type is uploaded or stored on our servers.

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