I’ve fixed more CORS errors than I can count. They all look slightly different but most fall into the same handful of categories. Here are the seven you’ll see most often, with the exact fix for each.

Error 1: “No ‘Access-Control-Allow-Origin’ header is present”#

Access to fetch at 'https://api.example.com/users' from origin 
'https://myapp.com' has been blocked by CORS policy: No 
'Access-Control-Allow-Origin' header is present on the requested resource.

This is the most common CORS error. It means your server isn’t sending any CORS headers at all.