Is my YAML sent to a server?

No. All validation and conversion runs entirely in your browser using JavaScript. No data is transmitted to any server and nothing leaves your device.

Which YAML features are supported?

The built-in parser handles scalar values, mappings, sequences, block and flow style, comments, multi-line strings, null/boolean/number coercion, and basic anchor references. Complex YAML features such as custom tags, merge keys (<<), and multi-document streams are not fully supported. A notice is shown when the parser encounters unsupported syntax.

What does "Sort keys" do?

When enabled, all mapping keys at every nesting level are sorted alphabetically before output is generated. This makes it easier to find a specific key and keeps diffs clean in version control.

Can I convert JSON to YAML?

Yes. Paste valid JSON into the input field. The tool detects JSON automatically and converts it to YAML using either block style (human-readable, multi-line) or flow style (compact, single-line).

YAML Validator & Converter

Paste YAML or JSON, validate syntax, convert between formats, and copy or download the result — all client-side with no server round-trips.

YAML / JSON Input

Paste YAML or JSON here

Options

Indent

YAML style

Sort keys alphabetically

Limited YAML support: The built-in JavaScript parser handles common YAML patterns. Complex features such as custom tags, merge keys (<<), and multi-document streams may not parse correctly.

Paste YAML or JSON on the left, then click Validate & Convert.

Summary

Paste YAML or JSON, validate syntax, convert between formats, and copy or download the result — all client-side with no server round-trips.

How it works

Paste YAML (or JSON) into the input textarea.
Click "Validate & Convert" to check syntax and see a validation badge.
Select an output tab — Formatted YAML, JSON, or Compact JSON.
Adjust options such as indent width, sort keys, or YAML style, then click Validate & Convert.
Use the Copy or Download button to save the result.

Use cases

Validate Kubernetes manifests and Helm charts before applying them to a cluster.
Convert YAML configuration files to JSON for use with tools that require JSON input.
Pretty-print and sort keys in YAML files to enforce a consistent style across a team.

Frequently Asked Questions

Last updated: 2026-09-22 · Reviewed by Nham Vu