YAML vs JSON — and how to convert between them
YAML and JSON describe the same data with different philosophies. JSON is explicit: braces, brackets, quotes — machines love it. YAML is minimal: indentation and dashes — humans editing Kubernetes manifests and CI configs love it. Same tree, different spelling.
Conversion sounds trivial until YAML's personality shows up: significant whitespace, implicit typing (the infamous Norway problem, where NO becomes false), anchors, multiline strings. A converter that validates both sides and reports error positions keeps those surprises visible.
Open the free YAML ↔ JSON Converter — no signup, runs entirely in your browser.
How to use it
- Paste YAML or JSON — the tool converts in whichever direction you pick.
- Get clean output with 2 or 4-space indentation.
- Parse errors report line and column on either side of the conversion.
Why this one
- True bidirectional conversion, validated on both ends.
- Nested maps, lists, scalars, nulls and multiline strings all supported.
- Duplicate-key detection catches a classic silent YAML bug.
- Client-side only — configs with secrets never leave your machine.
Frequently asked questions
Is JSON valid YAML?
Yes — YAML 1.2 is a superset of JSON, so any JSON document parses as YAML as-is. The reverse is not true: YAML features like anchors and comments have no JSON equivalent.
Why does my YAML parse to something unexpected?
Implicit typing. Unquoted yes, no, on and off can become booleans; 1e3 becomes a number; leading zeros cause trouble. Quote scalars when the string form matters.
Why is YAML so strict about indentation?
Indentation IS the syntax — it replaces braces. Spaces only, never tabs, and consistent depth per level. Most YAML parse errors are indentation errors; the reported line points at the offender.