CORS is a security mechanism implemented by web browsers to restrict cross-origin requests. It requires the server to include specific headers in the response to indicate which origins are allowed to access the resource. The ‘Access-Control-Allow-Origin’ header is one of those headers.
To solve this issue, you can follow these steps:
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Check server-side configuration: Make sure that the server hosting the requested resource is configured to include the ‘Access-Control-Allow-Origin’ header in its responses. This header should contain either the specific origin that is allowed to access the resource or a wildcard “*” to allow access from any origin.
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Specify allowed origins: If you have control over the server hosting the resource, you can configure it to include the ‘Access-Control-Allow-Origin’ header and specify the specific origins that are allowed to access the resource. For example, if your client-side code is hosted on “
example.com,” the server should include the following header: Access-Control-Allow-Origin:example.com. This allows only requests originating from “example.com” to access the resource. -
Use wildcard ‘’ cautiously: If you want to allow access from any origin, you can include the wildcard “” in the ‘Access-Control-Allow-Origin’ header. However, be cautious when using this approach, as it allows any website to access your resource, potentially exposing sensitive information.
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Additional headers: Depending on your application’s needs, you may need to include other CORS-related headers, such as ‘Access-Control-Allow-Methods’ and ‘Access-Control-Allow-Headers’. These headers define the HTTP methods and headers allowed in cross-origin requests.
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Proxy servers: If your application is making cross-origin requests through a proxy server, ensure that the proxy server is correctly configured to pass the necessary CORS headers from the original server response to the client.