Retrofit is a library that makes parsing an API reaction simple and better for utilization in the application. Retrofit is a REST client for Java and Android that makes it moderately simple to recover and transfer JSON by means of a REST-based web service. In Retrofit, you can arrange which converter is utilized for the information serialization. Normally, for JSON, you utilize Gson, but you can add custom converters to process XML or different conventions. Retrofit utilizes the OkHttp library for HTTP requests.