JSON ⇄ YAML converter
Runs entirely in your browser. Your files and data never leave your device.
About this tool
Paste JSON to get the same data as YAML, or paste YAML to turn it back into formatted JSON. The converter parses your input, so it also catches syntax errors and reports where they are. Strings that look like other types, such as "true" or "3.14", stay quoted so the round trip does not change your data.
Why does it keep some strings quoted?
YAML treats bare words like true, false, null, and anything that looks like a number as their typed equivalents, not as strings. If your JSON has a string value of "true" or "3.14", converting it to YAML without quotes would silently turn it into a boolean or a number, which changes what your data means. This tool keeps those values quoted in the YAML output so a value that was a string stays a string, and converting back to JSON round-trips to exactly what you started with. It’s a small detail, but it’s the difference between a config value like a version string "3.14" staying text or turning into a float somewhere downstream.
What happens when my YAML or JSON has a mistake in it?
Both directions parse your input before converting it, so a missing colon, bad indentation, or an unclosed bracket gets caught and reported rather than silently producing garbage output. Indentation errors are one of the most common YAML mistakes, since the format uses whitespace to express structure instead of braces, so the parser’s job is largely to make sense of that whitespace consistently.
Does anything leave my browser?
No. Conversion runs entirely client-side in JavaScript, and nothing you paste is uploaded anywhere. That makes it safe to use with Kubernetes manifests, CI pipeline definitions, or config files that contain credentials, internal hostnames, or other values you’d rather not send to a server.
Common uses: rewriting a JSON config as YAML for Docker Compose or GitHub Actions, converting an OpenAPI spec between the two formats, or flattening a YAML file into JSON to feed a tool that only accepts JSON. The output follows YAML 1.2, which is a superset of JSON, and RFC 8259 on the JSON side.