What is CORS?ĬORS, or Cross-Origin Resource Sharing, is a method that tells browsers that it is okay to use an additional origin by using extra HTTP headers. Just keep in mind that this header must be set by the origin that is responsible for serving the resources. Therefore, the bank must set the Access-Control-Allow-Origin header as part of the response to safeguarding its resources. The website surreptitiously tries to connect to your bank in the background. Who is required to configure Access-Control-Allow-Origin?Ĭonsider the following example to determine who should set this header: You are looking at a website where songs can be seen and heard. The browser is informed by these which origins are permitted to send requests to this server. The key header for resource sharing between origins is Access-Control-Allow-Origin, though there are a few others. Your origin B must inform the browser that it is acceptable for me to receive resources from your origin to permit origin A to access your resources.īrowsers permit origins to share resources due to CORS.

The browser will deny my request and prevent me from accessing resources from to preserve your security. I want to obtain resources from origin B, which is, and origin A. Here is an illustration of how this is put into practice − Origin is a mix of port, hostname, and scheme, such as, rather than just the hostname. With CORS or cross-origin resource sharing, browsers can permit a website hosted at origin A to request resources from origin B. In this tutorial, we will learn how access control allows the origin header to work.Īccess-Control-Allow- Origin is a header for CORS.

Access control allow origin' header