YAML ↔ JSON Converter
Convert between YAML and JSON formats with a built-in parser — no libraries required.
What this YAML and JSON converter does
YAML and JSON are two popular ways to represent structured data. JSON uses braces, brackets, and quotes and is the standard for web APIs, while YAML uses indentation and is favoured for human-edited configuration files such as those used by Docker Compose, Kubernetes, and CI pipelines. This tool converts in both directions so you can move data between the two formats without rewriting it by hand.
It is useful for developers translating an API response into a readable config, or turning a YAML config into JSON for a tool that only accepts JSON. Both conversions run instantly as you work.
How to use it
Pick a direction with the YAML to JSON or JSON to YAML tab. Paste your source into the input box on the left, then click Convert to see the result on the right. In JSON to YAML mode you also get a Validate JSON button that confirms your input parses correctly and reports the exact error if it does not.
Use Copy Output to copy the converted result, or Clear Output to empty the result pane. The tool ships with sample YAML and JSON loaded so you can see the expected shape before pasting your own data.
How the conversion works and its limits
JSON parsing uses the browser's native JSON.parse, and YAML to JSON is handled by a built-in lightweight parser, so no external libraries are loaded. The converter understands the most common YAML features: nested mappings by indentation, sequences written with dashes, quoted and unquoted scalars, booleans, numbers, and null values written as null or a tilde.
Because the YAML parser is intentionally compact, advanced YAML features such as anchors and aliases, multi-document files separated by triple dashes, block scalar folding, and complex inline flow structures are not fully supported. For everyday configuration data and API payloads it works well, but for exotic YAML you may need a dedicated parser.