Convert TypeScript interfaces, types, and classes into JSON Schema, then open the Mock Generator to craft matching sample JSON.
Select which interface/type should be treated as the JSON Schema root.
Parsing runs entirely in your browser. Your source never leaves the page.
Paste your TypeScript types to produce JSON Schema instantly.
Supports interfaces, type aliases, public class fields, optional/readonly modifiers, and union types.
This online TypeScript interface to JSON Schema converter helps you generate JSON Schema from real models (DTOs, structs, and classes) so you can validate payloads, share contracts, and generate mock JSON.
Step 1 – Paste your TypeScript source
Step 2 – Select the Root type (if needed)
Step 3 – Review the JSON Schema output
definitions and $ref when your models reference other models.Step 4 – Validate or generate mock JSON
anyOf/oneOf/allOf), verify the result with a full validator like Ajv.Schema keyword support note
Generated schemas can include $ref and may be edited to include anyOf, oneOf, or allOf. For complex schemas, use a full JSON Schema validator and dereference before mock generation if needed.
Use these tools to validate schemas, generate mock payloads, format JSON examples, and keep code and contracts in sync.
Generate example JSON from your schema for testing, fixtures, and documentation.
Validate JSON against common schema keywords and find mismatches quickly.
Transform JSON structures into TS interfaces.
Build schema from representative JSON samples to complement model-first schemas.
Explore schema examples and patterns for objects, arrays, enums, and constraints.
Clean up JSON examples before validating against schema or sharing docs.
Interfaces, type aliases, and classes with public fields are parsed. Optional properties, readonly modifiers, string-literal keys, union types, arrays, Record types, and nested references are handled. Comments and decorators are ignored so you can paste DTOs directly from your project.
Primitive types (string, number, boolean, bigint, Date) map to JSON Schema primitives with appropriate formats. Arrays (Foo[] or Array<Foo>), Record<string, T>, and dictionary-like shapes become schema arrays/objects. Union types that include null/undefined automatically mark the field as optional.
Yes. As long as the class defines public fields (or readonly properties) with type annotations, it will be converted into JSON Schema. The tool works entirely in your browser, so no code leaves your machine.
After the schema is generated, click "Generate Mock Data" to open the Mock Generator with the schema preloaded. Configure locales, array sizes, and optional fields to produce sample payloads instantly.