CORS Policy Checker

Test Cross-Origin Resource Sharing (CORS) policies by sending preflight requests and analyzing the server's CORS configuration. Check if your origin is allowed to access the target resource.

CORS Examples

CORS Test Configuration

About CORS

What is CORS?

Cross-Origin Resource Sharing (CORS) is a security mechanism that allows or restricts web pages from making requests to a different domain, protocol, or port than the one serving the web page.

Preflight Requests

For certain requests, browsers send a preflight OPTIONS request to check if the actual request is allowed. The server responds with CORS headers indicating permissions.

Common CORS Headers

  • Access-Control-Allow-Origin: Allowed origins
  • Access-Control-Allow-Methods: Allowed HTTP methods
  • Access-Control-Allow-Headers: Allowed request headers
  • Access-Control-Allow-Credentials: Cookie support