YAML ↔ JSON Converter — Free Online Tool

YAML ↔ JSON Converter — Bidirectional, Live Conversion

Convert between YAML and JSON in both directions, instantly as you type. Supports nested objects, arrays, strings (plain and quoted), numbers, booleans, null, comments, and flow-style sequences/mappings. Useful for config files, API payloads, CI/CD pipelines, Kubernetes manifests, and anywhere YAML and JSON are interchangeable. Everything runs in your browser — no uploads.

Supported YAML features

• Mappings: key: value
• Sequences: - item or flow [a, b, c]
• Nested structures: objects of arrays of objects, etc.
• Scalars: plain strings, single/double-quoted strings, integers, floats, booleans (true/false/yes/no), null (~/null)
• Flow style: {key: value, other: 1} and [1, 2, 3]
• Comments: # this is ignored
• Document markers: --- and ... are skipped

Limitations

This converter implements a common YAML subset. The following advanced features are NOT supported: multi-line block scalars (| and >), anchors and aliases (&, *), tags (!!), and complex keys. For 99% of config files this is plenty — but if you have YAML using those features, you’ll need a specialized library.

Common uses

• Converting Kubernetes/Docker Compose YAML manifests to JSON for API calls
• Converting JSON config to YAML for human editing
• Cleaning up YAML formatting and standardizing indent
• Sorting keys alphabetically for diff-friendly configs
• Validating that YAML actually parses correctly

Privacy

Everything runs in your browser. Your configs never leave your machine.