OpenAPI / Swagger Validator
Validate OpenAPI 3 and Swagger 2 specs: required fields, path parameters, duplicate operationIds and broken $refs. Free and private: runs in your browser.
Paste an OpenAPI spec in YAML or JSON to find errors that break code generators and documentation.
Runs entirely in your browser. Nothing you paste is uploaded or stored.
Use cases
- Find a syntax error before the build or deploy fails.
- Check config files in code review.
- Learn the rules your linter enforces.
Frequently asked questions
Why do operationIds matter?
SDK generators use them as method names. Missing or duplicate operationIds produce unusable or clashing client code.
Is the OpenAPI / Swagger Validator free?
Yes. It is free with no sign-up, and it runs entirely in your browser, so your input is never uploaded or stored.
What should I do with the issues it reports?
Fix high-severity items first; they usually break builds or deployments. Lower-severity items are style and best-practice suggestions.
Related tools
Checking one snippet is a start. Scan your whole repository for free with CodeInspector.