Open API Validator

Validate your OpenAPI/Swagger specification for errors and best practices.

Specifica OpenAPI / Swagger

All Tools

Come utilizzare OpenAPI Validator

Provide specifics

Attach the OpenAPI 3.x or Swagger 2.x specification in JSON format to the textarea, or load a .json/.yaml/.yml file, or press "Load Example" to start with a valid reference schema.

Start validation

Validate OpenAPI for structural check: required fields, operations, responses and $ref references.

Read the summary

Find the detailed format in the sidebar (OpenAPI/Swagger), title, version, number of paths, operations, schemas and tags, along with a summary verdict (valid, with errors or just warnings).

Filter and correct issues

Use counters "Errors", "Warnings", and "Info" to filter the list of found issues and correct each line individually.

Suggerimenti

  • Use "Load Example" to see an open OpenAPI 3.0.3 immediately and understand the expected structure.
  • Correct all critical errors first (blocking for generating SDK/documentation), then move on to warnings to improve the quality of the spec.
  • Every "$ref" must point to a defined schema in the same document: if you generate this spec with OpenAPI Spec Generator, validate it always before publishing.

Domande frequenti

What standards does the validator support?

OpenAPI 3.x (detected from the field "openapi") and Swagger 2.x (detected from the field "swagger"), both in JSON format, with the tool automatically identifying which one you are using.

What critical errors do you identify?

Missing required fields ("openapi"/"swagger", "info.title", "info.version", "paths"), paths without initial '/', HTTP methods missing, responses absent and references to "$ref" that do not point to a defined schema in components/schemas or definitions.

What are warnings?

Concise suggestions for best practice non-blocking: missing "info.description", "operationId", "summary"/"description" on the operation, "servers" (OpenAPI 3) or "host" (Swagger 2), and missing description on individual responses.

Can I load a YAML file?

Upload accepts .json, .yaml, and .yml files, but the validation parser only processes JSON; if you load a pure YAML file (not JSON), validation will report a parsing error. Convert your file to JSON before validating correctly.

Are attached or uploaded data sent to a server?

No. Pure logic executed in the browser, with no external NPM dependencies and no network calls: it stays on your device.