CORS Header Validator
Validate Cross-Origin Resource Sharing (CORS) headers for security and compliance
Request Configuration
The URL making the cross-origin request
The API/resource URL being requested
Enter response headers from the server (one per line, in "Name: Value" format)
CORS Headers Reference
Response Headers:
Access-Control-Allow-Origin- Allowed originsAccess-Control-Allow-Methods- Allowed HTTP methodsAccess-Control-Allow-Headers- Allowed request headersAccess-Control-Allow-Credentials- Allow cookies/authAccess-Control-Max-Age- Preflight cache durationAccess-Control-Expose-Headers- Exposed response headers
Best Practices:
- • Avoid wildcard (*) in production
- • Use specific origins when possible
- • Be cautious with credentials
- • Limit allowed methods and headers
- • Use HTTPS for secure applications
- • Set appropriate cache duration
For detailed CORS documentation, visit theMDN CORS Guide
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