API Development & Testing Tools

Explore self-hosted API development and testing solutions. Browse open source alternatives to Postman and Swagger for API design, documentation, and automated testing.

Scalar

11,821459

Scalar is an offline-first, open-source API client designed for modern developers working with OpenAPI/Swagger.

openapi-client

api-tools

swagger-ui-alternative

Last updated: 8/28/2025459 contributors