To resolve CORS issues, ensure your server is configured to send the appropriate headers allowing cross-origin requests.

CORS (Cross-Origin Resource Sharing) issues in your Node.js application can prevent your frontend from accessing resources hosted on a different origin, leading to frustrating user experiences. To fix these issues, start by ensuring that your server is configured to send the appropriate headers that allow cross-origin requests. If you're using Express, you can use the cors middleware to simplify this process; install it via npm and include it in your application with options that specify which origins are allowed to access your resources. You might want to allow all origins during development, but be cautious when deploying to production—restrict access to trusted domains for security reasons. Double-check that you are setting the headers correctly; the Access-Control-Allow-Origin header must match the requesting origin, or you can set it to * to allow all origins, although this is not recommended for production environments. Additionally, verify that your server handles preflight requests by responding to OPTIONS requests with the correct headers, including Access-Control-Allow-Methods and Access-Control-Allow-Headers. Review any potential proxy configurations in your deployment setup, as proxies can also affect CORS behavior. By systematically addressing these aspects, you can resolve CORS issues and ensure smooth cross-origin interactions in your Node.js application.