CORS Tester
Run a bounded CORS preflight check and report response headers.
CORS Tester helps you debug cross-origin request behavior before a browser blocks an API call. It is useful for frontend developers and API teams.
CORS Tester
Enter the required values and run the tool to view results.
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About the CORS Tester
Enter an endpoint and origin to run a bounded preflight-style check and inspect CORS headers. The report helps explain whether a browser is likely to allow the request.
Common uses
- Check Access-Control-Allow-Origin.
- Debug API preflight failures.
- Review allowed methods and headers.
Tips for Using CORS Tester
CORS is a browser access-control mechanism, not authentication. Avoid using permissive wildcard rules for sensitive endpoints.
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