CORS Tester
Test CORS headers for any URL. Sends a real fetch request with mode: 'cors' from your browser.
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URL
Method
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Mobile inline (between input and results)
Enter a URL and click "Test CORS" to check CORS headers.
Limitations
- Browsers restrict which headers are visible on CORS responses. Only CORS-safelisted response headers are exposed unless the server sends
Access-Control-Expose-Headers. - If the server blocks CORS entirely, the browser cannot read any headers or status code -- you will only see "CORS Blocked."
- This test runs from your current browser origin. Results may differ for other origins.
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