OpenAPI to JSON Schema Converter — Free Online

Extract OpenAPI 3.0–3.2 components.schemas into JSON Schema — default Draft 2020-12 ($defs), optional Draft-07 (definitions). Browser-local, no upload.

0 chars · 0 B

Draft

Share this tool:

OpenAPI document

JSON Schema

Conversion runs in your browser — nothing is uploaded.

Loading…

OpenAPI to JSON Schema documentation

Extract OpenAPI components.schemas into JSON Schema (2020-12 or Draft-07).

Developer notes

• OpenAPI 3.0 schemas convert via @openapi-contrib/openapi-schema-to-json-schema. • OpenAPI 3.1 / 3.2 use a best-effort strip of OAS-only keywords. • Default output: $schema 2020-12 + $defs; optional Draft-07 remap ($schema + definitions + #/definitions refs). • Empty components.schemas → error. • External $ref rejected. • Max input 512 KiB.

Options

Target draft

2020-12 (default) emits $schema + $defs. Draft-07 remaps to the Draft-07 $schema URI, definitions instead of $defs, and #/definitions/… refs — a structural rename only; 2020-12-only keywords are not rewritten.

Use cases

• Reuse OpenAPI models as standalone JSON Schema. • Feed extracted schemas into JSON Schema Validator. • Diff schema shapes outside of a full OpenAPI document.

Examples

OpenAPI YAML → JSON Schema $defs

Before

openapi: "3.0.3"
info:
  title: Pets
  version: 1.0.0
paths: {}
components:
  schemas:
    Foo:
      type: object
      properties:
        id:
          type: string
    Bar:
      type: object
      properties:
        name:
          type: string

After

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$defs": {
    "Foo": { ... },
    "Bar": { ... }
  }
}

Empty schemas rejected

Before

openapi: "3.0.3"
info:
  title: t
  version: "1"
paths: {}
components:
  schemas: {}

After

Error: empty components.schemas

OpenAPI to JSON Schema FAQ

Common questions

Is 3.1 conversion identical to Draft-07?

No. OpenAPI 3.1/3.2 conversion is a best-effort keyword strip. Default output is Draft <strong>2020-12</strong> (<code>$defs</code>). Choose <strong>Draft-07</strong> for a structural remap (<code>definitions</code> + Draft-07 <code>$schema</code>) — not a full keyword rewrite. See Options.

What if there is no Root schema?

All schemas land under <code>$defs</code> (or <code>definitions</code> when Draft-07 is selected) with no invented root type/properties. A schema named Root also gets a top-level <code>$ref</code> to that entry.