CORS Debugger & Fixer
End the frustration. Analyze your endpoint's cross-origin policy and generate the exact middleware fix for your backend in seconds.
The CORS Mechanism
CORS (Cross-Origin Resource Sharing) is a security protocol implemented by browsers. It prevents a website at domain-a.com from accessing resources at api-b.com unless the destination explicitly "allows" it via HTTP headers.
Using * (Wildcard) for origins is dangerous in production. It allows any website to call your API. Always specify your frontend domain for maximum security.
Troubleshooting Tips
Check Preflight (OPTIONS)
For "unsafe" methods like POST or DELETE, browsers send an OPTIONS request first. Ensure your backend handles it.
Allowed Headers
If sending custom headers (like Authorization), ensure they are listed in Access-Control-Allow-Headers.
Credentials Mode
If sending cookies, Access-Control-Allow-Credentials must be true and Origin cannot be a wildcard.
Common Inquiries
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