JSON ⇄ YAML
Convert JSON to YAML and YAML to JSON in one click. Paste either format and get a clean, validated conversion — ideal for config files, CI pipelines and Kubernetes manifests.
About the JSON ⇄ YAML
JSON and YAML describe the same kind of structured data, but YAML’s indentation-based syntax is easier for humans to write — which is why config files, CI pipelines and Kubernetes manifests favor it, while APIs favor JSON. Converting between them by hand is tedious and easy to get wrong with indentation.
This converter parses one format and re-serializes it as the other, preserving structure and types, and flags syntax errors. It runs entirely in your browser, so configuration that may contain sensitive values never leaves your machine.
The two formats reflect different priorities. JSON (a subset of JavaScript's object literal syntax, standardized as its own spec in the 2000s) optimizes for being trivial for a machine to parse and generate — every structure is explicit, wrapped in braces and brackets. YAML ("YAML Ain't Markup Language") optimizes for human readability: structure comes from indentation rather than punctuation, and it adds comments (# like this), which JSON has no syntax for at all — a genuine practical reason teams pick YAML for hand-maintained config despite JSON's simplicity.
That readability comes with sharp edges: YAML's indentation-sensitivity means a single misplaced space silently changes meaning rather than throwing an error the way a missing brace in JSON usually would, and YAML has a long history of surprising type coercion (an unquoted `no` or `yes` parsing as a boolean, `NO` the country-code-like string sometimes not) — case in point, this is exactly the kind of formatting subtlety a validating converter like this one exists to catch before it reaches a CI pipeline or a Kubernetes cluster.
How to use it
- 1Choose the conversion direction (JSON→YAML or YAML→JSON).
- 2Paste your source document.
- 3Copy the converted output.
Features
- Convert both directions: JSON → YAML and YAML → JSON
- Validates input and reports errors
- Preserves nesting, arrays and types
- Configurable JSON indentation
- One-click copy of the result
Frequently asked questions
How do I convert JSON to YAML?
Select the JSON → YAML direction, paste your JSON, and the equivalent YAML appears instantly, ready to copy.
Is YAML a superset of JSON?
Yes — any valid JSON is also valid YAML. This tool produces clean, idiomatic YAML rather than JSON-style YAML.
Does it validate my input?
Yes. If the JSON or YAML is malformed, the tool reports the error instead of producing bad output.
Is my data private?
Yes. Conversion runs entirely in your browser; nothing is uploaded.
Why do Kubernetes and CI tools use YAML instead of JSON?
YAML supports comments and reads more like structured prose than JSON's bracket-and-brace syntax, which matters a lot for files humans hand-edit and review, even though JSON is simpler for a machine to parse.
Why is YAML sometimes described as error-prone?
Because structure comes from whitespace indentation rather than explicit braces, a single misplaced space can silently change the document's meaning instead of causing an obvious parse error — and unquoted values like yes/no or on/off can be interpreted as booleans unexpectedly. A validating converter catches these before they cause a deploy failure.
Can every JSON document convert to YAML and back losslessly?
Yes for standard JSON — every JSON value has a direct YAML equivalent. The reverse isn't always true, since YAML supports features (anchors, multi-document files, comments) that have no JSON equivalent and get dropped or flattened when converting to JSON.