DevToolsmith

OpenAPI to JSON

Convert a Swagger or OpenAPI specification to JSON in your browser. Review the result, then copy or download it without uploading the document.

Runs 100% in your browser — nothing is uploaded

OpenAPI or Swagger source
Tip: drop a file here642 chars · 642 bytes · 34 lines
Converted JSON document
0 chars · 0 bytes · 0 lines

Swagger 2.0 and OpenAPI 3.0/3.1 · Local processing · Exact supported integer values · Duplicate keys rejected · YAML comments/layout are normalized.

Convert the file format

JSON and YAML can describe the same API contract. This tool recognizes Swagger 2.0 and OpenAPI 3.0/3.1 and exports the chosen serialization. It preserves supported integer digits and reports values that cannot be represented safely.

Review the contract separately

Changing serialization does not change the API version, resolve external files or prove that endpoints behave as documented. Open OpenAPI and Swagger Validator to check structure and preview complete documentation.

Frequently asked questions

Which API specification versions can I convert?

Swagger 2.0 and OpenAPI 3.0 / 3.1 are recognized. Conversion changes serialization, not the API specification version. It does not upgrade Swagger to OpenAPI.

Does conversion validate the API contract?

No. Convert supported values first, then use OpenAPI Validator for structural and local-reference checks. External references are kept as references and never fetched. YAML comments and layout are normalized; duplicate keys and unsupported numeric loss are rejected.