Postman

Postman is the industry-standard platform for API development. I use it primarily for manual testing and for building request collections that document an API while also verifying it.

The collection runner lets you chain requests together and use variables passed from one response into the next request. This makes it easy to script an entire authentication + data-fetch flow and run it as a suite.

For team work, shared Postman workspaces allow everyone on the team to access the same environments and collections so that testing stays consistent. The mock server feature is also useful for building frontend UI before the backend endpoint exists.

My main gripe with Postman is that it has become quite heavy over the years. For simple one-off requests I tend to use Insomnia instead, but for anything that needs to be documented and shared, Postman wins.