Swadit is a visual editor for Swagger/OpenAPI files supporting the ‘API first’ approach: Design your API first, then start coding with generated code stubs!
You can try it out for free (no account/login needed): https://swadit.froschbach.io.
Features Currently supported features include:
Design your REST API visually (no need to understand the Swagger/OpenAPI specification). Preview your API with a single click in Swagger UI. Open/save your API as Swagger/OpenAPI 2.0 file. For the expert: Edit the Swagger/OpenAPI source of your API in YAML format (with validation).