The URL of the API definiton is displayed in the top bar of Swagger UI – in your example it's

/v2/api-docs?group=full-petstore-api

So the full URL appears to be

http://localhost:8080/v2/api-docs?group=full-petstore-api

In newer versions of Swagger UI, the link to the API definition is often displayed below the API title, so you can right-click the link and Save As.

If your Swagger UI does not have a visible link to the API definition, view the page source and look for the url parameter, such as:

const ui = SwaggerUIBundle({
  url: "https://petstore.swagger.io/v2/swagger.json",     // <-------
  dom_id: '#swagger-ui',

If you don't see the url or if url is a code expression, open the browser dev tools, switch to the Network tab and disable caching. Then refresh the page and search for the API definition file (swagger.json, swagger.yaml, api-docs or similar) among HTTP requests. You can filter by XHR to narrow down the list.

Another way to find the actual url is to use the browser console and evaluate one of the following values, depending on your UI version:

• Swagger UI 3.x and later:

  ui.getConfigs().url
  

• Swagger UI 2.x:

  swaggerUi.api.url
  

Sometimes the OpenAPI definition may be embedded within a .js file – in this case take this file and strip out the extra parts.