Setting up CORS with Python Mar 02, 2019 What is CORS? CORS (Cross Origin Resource Sharing) allows access to resources from other domains, a good use case for this is a web app trying to fetch data from an API on another domain. CORS is only required when trying to fetch data from a browser, as browsers by default will block requests to different origins (domains). CORS uses HTTP headers to tell the browser if it has permission to fetch the resources. ...