OpenAPI Validator
Validate OpenAPI 3.0/3.1 YAML/JSON and locate errors
Syntax and structure issues appear here.
About this tool
Checks OpenAPI 3.0 and 3.1 YAML or JSON documents in the browser, reporting syntax and common structural issues with line and column context when available. It verifies required metadata, path formatting, and operation responses so you can catch practical API contract mistakes before review. This is a focused client-side validator, not a replacement for every vendor-specific rule or external reference resolver.
Frequently Asked Questions
Which OpenAPI versions are supported?
The checker accepts OpenAPI 3.0.x and 3.1.x documents written as YAML or JSON.
What does the browser check?
It parses syntax and checks common structure such as info metadata, paths, valid path keys, and responses on operations.
Does it resolve external references?
No. External files and remote references are intentionally not fetched, keeping validation private and deterministic in the browser.
Will errors include line and column details?
YAML parser errors include line and column context when the parser provides an offset; structural messages include the relevant JSON-style path.
Is this a complete official OpenAPI conformance test?
No. It is a focused structural validator for common authoring mistakes, so use your CI or vendor validator for exhaustive conformance.
Are my API definitions uploaded?
No. YAML parsing and checks run locally in the browser.
Keep browsing