Convert YAML to JSON Schema online, free. YAML is an indentation-based superset of JSON favoured for human-edited config. JSON Schema is a vocabulary for validating and documenting the shape of JSON data. YAML to JSON Schema conversion parses your YAML against the YAML 1.2.2 grammar (https://yaml.org/spec/1.2.2/), builds an in-memory model of its keys, nested objects and arrays, then derives a JSON Schema that describes that shape following the JSON Schema 2020-12 conventions. Processing runs in your browser in JavaScript with no upload or server round-trip — no size limit beyond your device's memory, so multi-megabyte documents convert in milliseconds and sensitive payloads never leave your machine. Typical uses include API request/response validation, form generation and contract testing.
It maps the full structure of your YAML onto a valid JSON Schema, following the JSON Schema 2020-12 conventions. 100% free, no registration, and complete privacy — everything runs locally in your browser, so your data never touches a server.
Paste YAML and derive a JSON Schema from JSON Schema immediately. Conversion runs client-side, so there is no upload wait and large documents stay fast.
Nested YAML objects, tables and arrays are mapped faithfully onto JSON Schema.
Your YAML never leaves your device — everything is processed locally in JavaScript, with nothing logged or stored.
Unlimited conversions with no account, no quotas, and no watermark. Works on desktop and mobile.
A YAML document and its JSON Schema equivalent:
YAML input:
label: web
replicas: 3
exposed: falseOutput:
{
"type": "object",
"properties": {
"label": { "type": "string" },
"replicas": { "type": "integer" },
"exposed": { "type": "boolean" }
},
"required": ["label", "replicas", "exposed"]
}Paste your YAML into the editor and press "Convert to JSON Schema". The tool parses it against the YAML 1.2.2 grammar, then derives a JSON Schema following JSON Schema 2020-12 conventions — instantly and entirely in your browser. You can validate or format the YAML first to be sure it is clean.
YAML anchors and aliases are expanded and comments are dropped before JSON Schema is produced, and indentation defines the structure. Note that YAML 1.1 treats words like "yes" and "no" as booleans, so quote them if you want strings.
The derived JSON Schema records the required keys and the value type of each field seen in your YAML sample. Widen it by hand if some fields are optional or can hold more than one type.
YAML (YAML Ain't Markup Language) (YAML) — YAML is an indentation-based superset of JSON favoured for human-edited config. JSON Schema (JSON Schema) — JSON Schema is a vocabulary for validating and documenting the shape of JSON data. This converter maps the structure of your YAML onto JSON Schema so you can use it for API request/response validation.
Yes. Invalid YAML is flagged with a clear error before anything is converted. Common YAML problems to check are spaces (never tabs) for indentation, consistent indent levels, and no duplicate keys. Starting from clean input keeps the generated JSON Schema accurate.
Yes. The entire YAML-to-JSON Schema conversion runs locally in your browser in JavaScript — your YAML is never uploaded, logged or stored. That matters when the data is something like Kubernetes & Docker Compose manifests, which should not leave your machine.
The generated JSON Schema is ready for API request/response validation, form generation and contract testing. Copy or download it and drop it straight into your validation or codegen pipeline.
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