YAML ↔ JSON Converter

It converts between the two formats in either direction: paste YAML and get JSON, or paste JSON and get YAML. Flip the direction with one toggle. It is handy when a tool wants one format but you have the other — for example turning a tidy YAML config into the JSON an API expects, or turning a block of JSON into YAML that is friendlier to read and edit. The conversion happens as you type.

The data is preserved — every key, value, list and nested structure comes across intact, and the order of keys is kept. Two things do not survive a round trip, because JSON simply has no equivalent: comments (the # lines in YAML) are dropped, and YAML anchors and aliases are expanded into the full data they stand for rather than kept as references. So the meaning of your document is identical; only YAML-only conveniences that JSON cannot represent are lost.

They describe the same kind of data, but suit different jobs. YAML is built for humans — it is the usual choice for configuration: CI pipelines, Docker Compose, Kubernetes and app settings, where comments and a clean layout matter. JSON is built for machines — it is what most APIs send and receive, and what many programs parse fastest. Converting lets you author in whichever is comfortable and hand over whichever the next tool requires.

Yes — it has to parse the input before it can convert it, so a syntax mistake is caught and reported with the line and column where parsing failed. That makes it a quick sanity check as well as a converter: if your YAML indentation is off or your JSON has a stray comma, you will see exactly where. It checks structure and syntax only — it does not know whether the values are the ones you meant.

It converts a single document at a time, which covers the overwhelming majority of config files. YAML lets you put several documents in one file separated by ---, and that multi-document form is not converted here; if you paste one you will see a parse error rather than a wrong result. Split the documents and convert them one by one. JSON has no multi-document concept, so the JSON-to-YAML direction always produces a single document.

No. Both directions are parsed and converted entirely in your browser — nothing you paste is sent to a server, which you can confirm in your browser’s network panel. That matters because YAML and JSON config so often holds hostnames, environment values, keys and other details you would not want to send to a third party. The optional share link keeps the input in the URL itself rather than on a server, and the on-device history can be cleared whenever you like.