JSON to OpenAPI schema
Generate an OpenAPI component schema from sample JSON in one click.
Objects and arrays are mapped to JSON Schema with required fields, and mixed arrays become oneOf definitions.
Everything runs locally in your browser—no data is sent anywhere.
How to use & features
- Paste JSON into the input and hit “Convert to OpenAPI.”
- Objects expand into JSON Schema with properties plus a required array.
- Arrays infer the element type; if multiple types appear, the tool outputs oneOf.
- Use copy or clear to reuse the schema or start fresh.
Sample input & output
Infer schema from a profile object
Input
{"name":"Jane","email":"jane@example.com","verified":true}Output
{
"type": "object",
"properties": {
"name": {"type": "string"},
"email": {"type": "string", "format": "email"},
"verified": {"type": "boolean"}
},
"required": ["name", "email", "verified"]
}Frequently asked questions
What does the output look like?
How are mixed arrays or nulls handled?
Is any data sent to a server?
Common use cases
Drafting schemas
Transform JSON samples into OpenAPI schema stubs to seed documentation or mock generation.
Sharing endpoint expectations fast
Convert request/response examples and paste them into PRs or issues to align on contract details.
Checking consistency with existing specs
Compare generated stubs with current definitions to spot fields that need updates.
Notes & limitations
Work stays in your browser
Inputs and outputs remain local. Closing the tab or clearing cache will remove any temporary state.
Validate critical data
Results are helper outputs—double-check them before sending to production systems or sharing externally.
Large payloads depend on your device
Very large text or files can feel slow in some browsers. Use a desktop environment for heavy workloads.