https://echo.hoppscotch.io
Description: Echo server is an application that allows a client and a server to connect so a client can send a message to the server and the server can receive the message and send, or echo, it back to the client.
https://jsonplaceholder.typicode.com/todos
JSONPlaceholder is a free online REST API that you can use whenever you need some fake data. It can be in a README on GitHub, for a demo on CodeSandbox, in code examples on Stack Overflow, ...or simply to test things locally.
https://reqres.in/api/users
Reqres simulates real application scenarios. If you want to test a user authentication system, Reqres will respond to a successful login/register request with a token for you to identify a sample user, or with a 403 forbidden response to an unsuccessful login/registration attempt.