CORS Policy Tester
Test and debug Cross-Origin Resource Sharing policies for any endpoint
Comma-separated header names
CORS Headers Analysis
Raw Response Headers
Status
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CORS Allowed
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Credentials
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Note: This tool makes a real request from your browser. Some servers may block the request due to their CORS policy, which is itself useful diagnostic information.
Understanding CORS
How Cross-Origin Resource Sharing protects web applications
What is CORS?
CORS is a security mechanism that allows servers to specify which origins can access their resources. Browsers enforce these policies to prevent unauthorized cross-origin requests.
Preflight Requests
For non-simple requests, browsers send an OPTIONS preflight request first to check if the server allows the actual request method, headers, and origin.
CORS and Auth
Authentication APIs must configure CORS carefully to allow frontend applications to send credentials while preventing unauthorized origins from accessing protected endpoints.
CORS issues with your auth provider?
AuthAction handles CORS configuration automatically for all your authentication endpoints.