Web Api 2 Preflight CORS request for Bearer Token

Question

I have a web-app with an AngularJS front-end and a Web Api 2 back-end, and it uses bearer-tokens for authentication.

All is well in FireFox & IE, but with Chrome

Answer 1

By default - Access-Control-Max-Age: seconds is 0 and your requests not caching.

Try set it to max value: (Owin selfhost). It solve problem with extra OPTIONS requests

            app.UseCors(new CorsOptions
            {
                PolicyProvider = new CorsPolicyProvider
                {
                    PolicyResolver = context => Task.FromResult(new CorsPolicy
                    {
                        AllowAnyHeader = true,
                        AllowAnyMethod = true,
                        AllowAnyOrigin = true,
                        SupportsCredentials = false,
                        PreflightMaxAge = Int32.MaxValue // << ---- THIS
                    })
                }
            });