APIForge

Swagger 2.0 validator online

Paste a swagger.json or swagger.yaml URL, or a Swagger UI page. APIForge parses the Swagger 2.0 file, resolves its definitions, builds the server URL from host, basePath and schemes, and lists every operation with its parameters.

No spec handy?
  • Swagger 2.0
  • JSON · YAML
  • Swagger UI links
  • OpenAPI 3.x too

What happens to your swagger file

  • The file is fetched on the server, with a 15 second timeout and a 15 MB limit.
  • JSON or YAML is parsed, and $ref pointers into definitions are resolved.
  • Operations are listed with parameters, body schema, responses and securityDefinitions.
  • The design is scored from 0 to 100 against seven rules, and you can send requests from the same workspace.

Not sure which file to paste? See how to get the OpenAPI JSON from a Swagger UI page. For the differences between the two formats, read Swagger vs OpenAPI.

Related tools

Frequently asked questions

Paste the URL of your swagger.json or swagger.yaml into the field above. A Swagger UI page works too. APIForge fetches the file on its server, parses it, resolves the definitions and lists every operation with its parameters. If nothing can be extracted, the parse error is shown.

OpenAPI 3.0 is the renamed and extended successor to Swagger 2.0. The visible changes: servers replaces host, basePath and schemes, components replaces definitions and securityDefinitions, requestBody replaces the body parameter, and consumes and produces move into content. The swagger-vs-openapi guide has the full mapping.

Open the Swagger UI page and look at the URL in its top bar, or check the browser network tab for a .json or .yaml request. You can also paste the UI page itself. APIForge tries common paths such as /swagger/v1/swagger.json and /v3/api-docs, and reads the Swagger UI initializer for the real one.

The common causes are a URL that returns HTML instead of the raw file, invalid JSON or YAML, no operations under paths, a URL behind authentication, or a file over 15 MB or slower than 15 seconds. The error message names the failure it hit last. If you pasted a UI page, try the raw JSON or YAML URL.

Yes. The server URL is built from schemes, host and basePath. If the spec lists no schemes, APIForge assumes https. A local $ref into definitions that points at nothing is replaced with an empty stub, so the file still loads.

No. APIForge reads Swagger 2.0 directly and shows its operations in the same workspace as OpenAPI 3 specs, so you can send requests, score the design and generate TypeScript types. It does not export a converted OpenAPI 3 file.

No. It loads specs the way Swagger UI does, so small spec violations do not block the load, and it does not report line numbers. It confirms that the file parses, the references resolve and the operations can be listed. Use a schema-based linter in CI if you need strict conformance.

The parse request fetches the spec on the server, returns the operations to your browser and does not save the spec. APIForge is free, needs no account and is open source under the MIT license.