CORS Tester
Test cross-origin resource sharing policies
Test Results
Detected CORS Headers
How CORS Works
- Access-Control-Allow-Origin: Specifies which origins can access (*, specific domain, or null)
- Access-Control-Allow-Methods: HTTP methods allowed (GET, POST, etc.)
- Access-Control-Allow-Headers: Custom headers allowed in requests
- Access-Control-Allow-Credentials: Whether cookies/auth headers are allowed
- Preflight Request: Browser sends OPTIONS request first for complex requests