OpenAPI / Swagger Validator
Paste your OpenAPI 3.x spec to validate, browse endpoints, and find issues. Browser-only.
Paste your OpenAPI spec on the left to see validation results
Frequently Asked Questions
- What is OpenAPI?
- OpenAPI (formerly Swagger) is a standard for describing REST APIs. An OpenAPI spec is a YAML or JSON file that documents all your API endpoints, parameters, request bodies, and responses.
- What versions are supported?
- Full support for OpenAPI 3.0 and 3.1. Partial support for Swagger 2.0 (the tool will parse it but validation rules are optimized for OpenAPI 3.x).
- Why should every API have operationId?
- operationId provides a unique identifier for each operation. It's used by code generators (like openapi-generator) to name SDK methods, and makes it easier to reference specific operations in documentation.
- Is my API spec sent to a server?
- No. All parsing and validation happens entirely in your browser. Your API spec never leaves your device.
- What is the difference between OpenAPI 3.0 and 3.1?
- OpenAPI 3.1 aligns fully with JSON Schema, adds webhooks support, and allows multiple servers. Most tools support 3.0 more broadly, but 3.1 is more capable. This validator handles both.