Fiddler vs Sandbox: What are the differences?
What is Fiddler? *A free web debugging tool *. It is a free web debugging proxy for any browser, system or platform. It helps you debug web applications by capturing network traffic between the Internet and test computers. The tool enables you to inspect incoming and outgoing data to monitor and modify requests and responses before the browser receives them.
What is Sandbox? Quick and easy mock RESTful API and SOAP webservices. Quickly mock RESTful API or SOAP web-services with simple or dynamic responses, and fault injection to simulate real application behaviour.
Fiddler and Sandbox can be categorized as "API" tools.
Sandbox is an open source tool with 161 GitHub stars and 28 GitHub forks. Here's a link to Sandbox's open source repository on GitHub.