I am trying to make a CORS get request to my server. My server is properly CORS enabled. I am sending an additional header so preflighted option call is sent by browser. This is working in Chrome but not in firefox. In firefox i can see the options call with 200 as return status code but the subsequent get call is not sent which is happening perfectly in Chrome. My server is also using certificate issued by Global CA like DigiCert . This CA is present in Firefox trust list. In firefox i see these messages in console Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://serverurl. (Reason: CORS header ‘Access-Control-Allow-Origin’ does not match ‘https://tryit.w3schools.com, *’).[Learn More] Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://serverurl. (Reason: CORS request did not succeed).[Learn More] I am making XMLHttpRequest call to trigger the call. I am not able to figure why the call is failing in firefox Best Regards, Saurav