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CORS Test Tool

Test CORS headers for a given URL

Test CORS

Enter an API endpoint to test its CORS configuration

About CORS

CORS (Cross-Origin Resource Sharing) is a security feature implemented by browsers to control how web pages can request resources from different domains.

CORS Headers:

  • Access-Control-Allow-Origin
  • Access-Control-Allow-Methods
  • Access-Control-Allow-Headers
  • Access-Control-Allow-Credentials
  • Access-Control-Max-Age

Common Issues:

  • Missing CORS headers
  • Restricted origins
  • Method not allowed
  • Preflight request failures
  • Credential issues

How It Works

  1. Browser sends preflight OPTIONS request
  2. Server responds with CORS headers
  3. Browser checks if origin is allowed
  4. If allowed, actual request is sent
  5. Server responds with data and CORS headers