ReqRes - A hosted REST-API ready to respond to your AJAX requests.
JSON Server - Get a full fake REST API with zero coding in less than 30 seconds. For front-end developers who need a quick back-end for prototyping and mocking
JSON Placeholder - JSON Placeholder is a modern platform that provides you online REST API, which you can instantly use whenever you need any fake data.
Parse-Server - parse-server. Parse-compatible API server module for Node/Express. JS, 14271, 3819. parse-server-conformance-tests. Conformance tests for parse-server adapters.
JsonAPI - Application and Data, Languages & Frameworks, and Query Languages
JSONBase - API based JSON storage