Recommended and mentioned products
Open source API development ecosystem
There are really goods suggestions in this thread, I just made a compilation of all the links posted (at this time): Restfox https://restfox.dev/ Hoppscotch https://hoppscotch.io/ Hit https://hit.yolo42.com/ HTTP Client https://www.jetbrains.com/help/idea/http-client-in-product-code-.
Hurl is a command line tool that runs HTTP requests defined in a simple plain text format.
I have been trying out https://hurl.dev and so far been really liking it. Plain text format, everything runs very quickly locally, it can capture data from previous requests to run workflows and serve as a testing tool.
Paw is a REST client for Mac.
Switched away from Postman to a native Mac app and my RAM couldn't be happier (https://paw.cloud).
The most intuitive cross-platform REST API Client ð´
I switched to insomnia when postman changed their pricing pulling the rug out from everyone wanting us to pay like $300 more per month. (Before they back tracked) https://insomnia.rest/ I actually prefer it.
Milkman is a JavaFx-based workbench for crafting requests / responses. It is not limited to e.g. http (or more specifically rest) requests but can be extended in any imaginable way. It is optimized for fast startup and efficient workflow.
Extension for Visual Studio - A set of extensions to Visual Studio 2012 Professional (and above) which improves developer productivity.
If you are a minimalist, and are using VS Code, try https://marketplace.visualstudio.com/items?itemName=humao.rest-client which is a pure text syntax to describe API requests, and execute them right from the editor window. I now have api.http text file in every API-first project I am building and I love it.
HTTP REST client tool for emacs
Although I mainly stick with curl or requests due to muscle memory, there's also restclient.el https://github.com/pashky/restclient.el. I imagine having builtin org support is super convenient, thanks for sharing.