FREE · DEVELOPER TOOLS
OpenAPI Viewer and Validator.
Open an OpenAPI 3 or Swagger 2 file to list every endpoint and check broken $refs, undeclared path parameters, duplicate operationIds, missing responses and security schemes, with curl examples.
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How to use OpenAPI Viewer and Validator
Open or paste a YAML or JSON API description. Read the endpoint table and the findings; copy the Markdown list or the curl commands.
How it works
The file is parsed as YAML or JSON; local $ref pointers are resolved, path templates are compared with declared path parameters and operationIds are counted.
Example
The Pet Store example lists 3 operations; renaming {petId} to {id} in the URL is reported as an undeclared path parameter.
Questions about OpenAPI Viewer and Validator
Is OpenAPI Viewer and Validator free, and do I need an account?
Yes. This tool is free to use in your browser without an account. Processing takes place on your device.
What are the limits and what should I check?
Structural checks only: not every JSON Schema keyword is validated and external $refs are not followed. Up to 20 MB. Everything is calculated in your browser; nothing you type is uploaded. Review the result before using it in your work.
Is my input sent to a server?
Your input is processed in your browser and is not uploaded by this tool. Files and pasted text are cleared when the page is refreshed. Normal website requests are still required to load the page and its libraries. Read the privacy explanation.