OpenAPI Specification vs Retrofit: What are the differences?

What is OpenAPI Specification? An API description format for REST APIs. It defines a standard, language-agnostic interface to RESTful APIs which allows both humans and computers to discover and understand the capabilities of the service without access to source code, documentation, or through network traffic inspection.

What is Retrofit? A type-safe HTTP client for Android and Java. Retrofit turns your HTTP API into a Java interface.

OpenAPI Specification and Retrofit can be categorized as "API" tools.

Retrofit is an open source tool with 33K GitHub stars and 6.13K GitHub forks. Here's a link to Retrofit's open source repository on GitHub.

Medidata Solutions, Kapten, and Unmetric are some of the popular companies that use OpenAPI Specification, whereas Retrofit is used by Square, Robinhood, and Samba Tech. OpenAPI Specification has a broader approval, being mentioned in 22 company stacks & 8 developers stacks; compared to Retrofit, which is listed in 19 company stacks and 7 developer stacks.