Turn any OpenAPI spec into clean TypeScript, instantly
Paste or upload an OpenAPI 3.x document in JSON or YAML. Get typed interfaces, enums, and an optional typed fetch client β generated live in your browser, with real parsing and zero mock data.
Built for real API workflows
Every feature runs against your actual schema β nothing here is a placeholder.
Full $ref resolution
Nested and circular $ref pointers inside components.schemas resolve correctly, including arrays of refs and combined schemas.
allOf / oneOf / anyOf
Composition keywords map to TypeScript intersections and unions instead of being flattened or dropped.
Enums as literal unions
OpenAPI enums become precise string or numeric literal unions, with an optional exported union alias.
Typed API client
Generates a small typed fetch wrapper with one function per operationId, using your real path, method, and parameter shapes.
Live input validation
A realtime listener checks JSON/YAML syntax and required OpenAPI fields as you type, before you ever hit generate.
Naming & formatting controls
Choose PascalCase or preserved names, 2/4-space or tab indentation, and readonly properties to match your codebase style.
Copy, download, or clear
One click to copy the generated .ts output, download it as a file, or clear the workspace and start again.
Dark & light themes
A persisted theme toggle keeps the interface comfortable whether you work at night or in a bright office.
Runs entirely in-browser
Parsing, resolution, and code generation execute in client-side JavaScript β your spec is never sent to a server.
How the OpenAPI to TypeScript conversion works
Four steps, all running locally in your browser.
Provide your spec
Paste OpenAPI 3.x JSON or YAML, or upload a .json/.yaml file directly from your project.
Parse & validate
The parser detects the format, checks required OpenAPI fields, and flags syntax issues in real time.
Resolve & map schemas
Every schema, $ref, and composition keyword is walked and mapped to the closest TypeScript construct.
Generate & export
Interfaces, enums, and an optional client are rendered, ready to copy or download as a .ts file.
What is an OpenAPI TypeScript generator, and why use one?
An OpenAPI TypeScript generator reads an OpenAPI (formerly Swagger) document and turns its schema definitions into TypeScript types your editor can check against. Instead of hand-writing an interface every time an API adds a field or renames a property, you regenerate the types straight from the source of truth: the spec itself. That keeps your frontend and backend contracts honest, especially on teams where the API changes weekly and nobody wants to chase down a silent runtime bug caused by a mismatched field name.
The conversion itself, openapi to ts in short, is really a structural mapping problem. Objects with properties become interfaces. Required fields stay required; everything else becomes optional with a question mark. Arrays map to T[], enums map to literal unions, and composed schemas built with allOf, oneOf, or anyOf map to intersections and unions respectively. A solid openapi typescript converter also needs to follow $ref pointers correctly, including ones that reference each other, without producing duplicate or broken type names.
So how do you actually use one? Start with a valid OpenAPI 3.0 or 3.1 document, either JSON or YAML, exported from your API framework, written by hand, or pulled from a live Swagger UI endpoint. Paste it into a generator like this one, review the parsed structure, and generate. A good example is a simple User schema with an id, an age, and a list of tags: the output should be a clean interface with the exact same shape, no extra wrapper objects, no renamed fields, and no fabricated data. If the tool also builds a typed client, each operation in your paths object becomes a callable function with parameters and a return type inferred from the response schema.
What separates a genuinely useful converter from a toy demo is that it works on real, sometimes messy specs: deeply nested refs, optional versus required fields handled precisely, and enums that don't silently become plain strings. Whether you are prototyping a new service, onboarding a third-party API, or keeping a monorepo's shared types in sync, converting OpenAPI to TypeScript directly from the spec removes an entire category of manual typo-driven bugs β and it takes seconds, not a sprint ticket.
Frequently asked questions
Paste your OpenAPI 3.x JSON or YAML document, or upload the file, into the generator above. It parses every schema under components.schemas, plus inline request and response bodies, and outputs an interface per object, a union type per enum, and an optional typed fetch client built from your paths.
Yes. The generator automatically detects whether your input is JSON or YAML and parses either directly in the browser, so you can paste a spec straight from Swagger, Redoc, or your own repository without pre-converting it.
No. Parsing and generation both run locally using JavaScript in your browser. Your spec β which may describe internal endpoints β never leaves your device.
Keep your API contracts in sync, automatically
Explore more free developer utilities, or jump straight into our JSON toolkit to shape data before it hits your types.