November 1, 2020

Swagger vs OAS

Let us Demystify this! People often get confused when they speak about Swagger and OAS (Open API Specification).

In 2010, Mr. Tony Tam started working on an uniform interface to design REST APIs and he named it as Swagger. The Swagger project was launched in 2011 to public.

Open API Intiative was started by industry leading experts to standardize API definitions.

In 2015, SmartBear took control of Swagger and donated only Swagger specification to Open API Initiative. And Swagger Specification remaned to Open API specification in Github.

Swagger Specification = Open API Specification

Swagger turned out to be a set of tools rather than specification. Swagger constitutes following tools:

  1. Swagger Editor
  2. Swagger UI
  3. Swagger Codegen
  4. Swagger Inspector
  5. Swagger Hub

In 2017, OAS version 3.0 launched. From then on, swagger is more like a toolkit  to design, document, build and inspect APIs whereas OAS remained as a rule book to specify how to design REST APIs.

Swagger vs OAS

Hope it is clear now that

  1. Open API specification was same as swagger initially.
  2. Later Swagger turned to be ToolSuite where as OAS remained as standardisation.

In Swagger editor, you can mention  swagger: 2.0 for open API 2.

But from OAS version 3, you must mention as openapi: "3.0.n".

swagger keyword is no longer entertained.

Thats all! Let us know if you have any further questions.