YAML Formatter & Validator

Validate YAML configuration files, pretty-print parsed data and convert YAML to JSON locally in your browser.

Input YAML

0 characters

Output

Result appears here. Everything runs in your browser.

Ready

Format options

Indentation Sort mapping keys Sort object keys alphabetically before formatting. Quote strings Use quoted scalar strings in formatted YAML.

Formatting rebuilds YAML from parsed data. Validate first if you only need to check syntax without changing comments or layout.

Configuration file checks

Check Kubernetes manifests, Docker Compose files, GitHub Actions workflows and OpenAPI snippets before committing them.

YAML to JSON preview

Convert parsed YAML into readable JSON when you need to inspect nested data or pass it to another developer tool.

Private local processing

The YAML text is handled by JavaScript in your browser. No upload endpoint is involved.

Related developer tools

JSON Formatter

Format, validate and minify JSON

YAML to JSON

Convert YAML files to JSON

JSON to YAML

Convert JSON files to YAML

URL Encoder & Decoder

Encode and decode URL text

Frequently Asked Questions

Is my YAML uploaded to Convertr?

No. The formatter runs in your browser using an open-source YAML parser. Your YAML text is not posted to Convertr servers.

What does the YAML validator check?

It checks YAML syntax, duplicate mapping keys and parse errors reported by the browser YAML parser. When available, line and column details are shown.

Can this tool format Kubernetes or GitHub Actions YAML?

Yes. Paste common YAML configuration files such as Kubernetes manifests, Docker Compose files, GitHub Actions workflows and OpenAPI snippets to validate and reformat them.

Will comments and anchors be preserved?

Validation reads the original YAML, but formatting rebuilds YAML from parsed data. Comments and some advanced presentation details may not be preserved in formatted output.