OpenAPI to TypeScript

Generate TypeScript interfaces from any OpenAPI 3.0 schema component.

Presets:

OpenAPI Schema (JSON)

Input Size

690 B

Input Lines

Interfaces

Output Lines

TypeScript Interfaces

export interface User {
  id: number;
  email: string;
  name?: string;
  active?: boolean;
  tags?: string[];
  address?: Address;
}

export interface Address {
  street?: string;
  city?: string;
}

About OpenAPI to TypeScript

This tool converts OpenAPI 3.0 schema definitions into TypeScript interfaces in your browser — nothing leaves your machine. Paste a full OpenAPI document (with a components/schemas block) or a single schema object and the generator produces one export interface per schema. Properties listed in required are emitted without the ? modifier; all others are optional. $ref pointers are resolved to their referenced interface name, integer and number both map to TypeScript's number, and typed arrays use the T[] syntax. Download the result as a .d.ts declaration file or copy it straight into your project.

Built and maintained by Meet Shah · Last updated 18 July 2026

What this tool is used for

Generating interfaces from a schema so a client is typed.
Producing types for an endpoint from its published spec.
Keeping client types in step with a spec change.
Getting a starting type set you then narrow by hand.
Comparing generated types across two spec versions.

Frequently Asked Questions

Which part of the spec is read?: components.schemas when present, which is where OpenAPI 3 keeps reusable models. A bare schema object is also accepted and emitted as a single interface, so you can paste a fragment without wrapping it in a full document.
How does required map to TypeScript?: A property listed in the schema's required array becomes a plain field; everything else gets ?. That is the correct reading — in JSON Schema a property is optional unless required, which is the opposite of TypeScript's default.
What happens to $ref?: The reference is resolved to its final path segment and used as the type name, so #/components/schemas/Address becomes Address. That matches the interface generated for that schema, so the two line up without an import.
Why did my string format not produce a narrower type?: Formats such as email, uuid and date-time are annotations on a string and have no TypeScript equivalent, so they map to string. Branding them into distinct types is a design decision this generator deliberately leaves to you.
Are enums, oneOf and allOf supported?: Not in this converter — it handles the object, array, scalar and $ref cases that make up the bulk of a typical schema. Compositional keywords need a union or intersection strategy, which is where a full code generator earns its complexity.
Does it accept YAML?: No, the input is parsed as JSON. Most editors and the Swagger UI will export or convert a YAML spec to JSON, and doing that conversion first keeps the error messages here about your schema rather than about indentation.

Common errors and gotchas

Trusting the spec, since generated types are only as accurate as the document they came from.
Losing nullability, where 3.0 and 3.1 express it differently and generators disagree.
Generating an any for a schema-less field, which pushes the problem to run time.
Assuming a required field is always present, when the server may not honour its own spec.
Regenerating over hand-edits, which then silently disappear.