Hoppscotch Community Edition is an open-source API development and testing tool for REST, GraphQL, WebSocket, SSE, MQTT, and Socket.IO with collections and environments.

80.1k stars6.1k forksMITlast commit Actively maintained
Apidog is a cloud API platform for designing and documenting REST APIs, creating mock servers, testing endpoints, and collaborating on API development. It provides API mocking, automated test runs, and documentation generation.
Hoppscotch Community Edition is an open-source API development and testing tool for REST, GraphQL, WebSocket, SSE, MQTT, and Socket.IO with collections and environments.

80.1k stars6.1k forksMITlast commit Actively maintained
Yaade is a self-hosted, collaborative API development environment that lets teams share API collections, run tests, and import from OpenAPI or Postman.

2k stars89 forksMITlast commit Slowing down
Every option on this page is open source and free to run on your own hardware, so you own the data and there is no subscription to cancel. 1 of 2 shipped a commit in the last six months. Licences in this list: MIT. In exchange you take on hosting, backups and updates yourself.
Browse everything in API Development, Mocking & Testing.