Coursera
Neither Postman nor Standard Library offers a free trial.
Postman is designed for Large Enterprises, Medium Business and Small Business.
Standard Library is designed for Individuals, Freelancers, Medium Business and Small Business.
Pricing for Postman Starts at $12/User/Month when Billed Yearly whereas for Standard Library Starts at $15/Month.
Some top alternatives to Postman includes Apigee Edge, WSO2 API Manager, SwaggerHub, API Fortress, BlazeMeter, TestMace, Insomnia CLI, Meta API, RestCase and Dapi.
Some top alternatives to Standard Library includes ApiWay, LinkApi, Meta API, API Maker, Codeless, Code2, NoCodeAPI, Merge, ApiX-Drive and Base API.