YAML Validator, Formatter & JSON Converter
Paste any YAML — Kubernetes manifests, GitHub Actions, docker-compose — and instantly validate, format, or convert to JSON. Browser-side only.
Your output will appear here.
What is yamlchop?
yamlchop is a free, browser-side tool for validating, formatting, and converting YAML. Paste any YAML document — a Kubernetes manifest, a GitHub Actions workflow, a docker-compose file, an Ansible playbook, or a Helm values file — and yamlchop tells you immediately whether it's valid and shows you a clean, formatted version.
The tool uses js-yaml, a battle-tested JavaScript YAML parser that implements the YAML 1.2 spec. Everything runs locally in your browser via a CDN-loaded script — your data never leaves your device. Take the page offline and it still works.
When YAML validation fails, yamlchop shows you the exact line and column where the parser got confused. Common issues include tab characters instead of spaces (YAML requires spaces), unquoted colon-containing values like message: hello: world, and inconsistent indentation levels. Fix the error, paste again, and iterate.
Use the Convert to JSON mode to transform your YAML into pretty-printed JSON — useful when you need to pass YAML-formatted config to an API that only speaks JSON, or when you want to inspect deeply nested structures in a JSON viewer. Use the JSON → YAML mode to go in the other direction: paste a JSON object and get clean YAML back.
Frequently asked questions
Is my YAML sent to a server?
No. yamlchop uses js-yaml, a JavaScript library that runs entirely in your browser. Your YAML is processed on your device and never transmitted anywhere. You can disconnect from the internet after the page loads — the tool still works.
What kinds of YAML does yamlchop support?
yamlchop supports YAML 1.2 including Kubernetes manifests, GitHub Actions workflows, docker-compose files, Ansible playbooks, Helm values files, CircleCI and GitLab CI configs, and any other standards-compliant YAML. Multi-document YAML (separated by ---) is fully supported — each document is parsed and re-formatted independently. In JSON conversion mode, multiple documents produce a JSON array.
Why does YAML validation fail on my Kubernetes manifest?
Common causes: inconsistent indentation (YAML requires spaces, not tabs), a colon followed by a space in a string value without quotes (e.g. message: hello: world needs quoting as message: "hello: world"), or special characters in unquoted strings. The error panel shows the exact line and column where the parser failed.
Can I convert JSON to YAML?
Yes — use the JSON → YAML tab. Paste valid JSON into the input panel and yamlchop converts it to clean, formatted YAML. Useful for converting API responses or configuration templates between formats.
Does yamlchop handle multi-document YAML?
Yes. yamlchop supports multi-document YAML streams separated by ---. In Format YAML mode, each document is parsed and re-formatted independently. In Convert to JSON mode, multiple YAML documents are returned as a JSON array.
Why does my YAML look different after formatting?
YAML formatting normalizes your input: consistent 2-space indentation, explicit quoting for strings that need it, and canonical key ordering where the YAML spec allows. The formatted output is semantically identical to your input — the data structure is unchanged. Comments are not preserved (the YAML spec does not require parsers to retain comments).
What is the difference between YAML and JSON?
YAML is a superset of JSON — any valid JSON is also valid YAML. YAML adds human-friendly features: indentation instead of braces, comments with #, multiline strings, and anchor/alias references for repeating values. JSON is more portable for API data because its syntax is explicit and unambiguous. YAML is preferred for config files because it is easier to read and write by hand.
Can yamlchop validate YAML against a schema?
Not yet — yamlchop currently validates YAML syntax (is it parseable YAML?) rather than semantic validity (does it match a specific schema like a Kubernetes CRD). Schema validation against JSON Schema is a planned paid feature. For Kubernetes specifically, kubectl apply --dry-run=client is the most reliable schema validator.